[TL;DR? – scroll down to to Summary section for the key points]

[Inspired by Jeremy Dover’s "Google (Maps) Hacking" puzzle. That and my previous puzzle on a similar subject may give "spoilers" for this one, or they may distract…]

I returned from what turned out to be a pleasant holiday after near-disaster. I called my Brazilian computer guy back round to fix my maps search properly this time.

He showed me Brazil again and said "What do you mean – look it’s still working". I showed him what happened when I type in other places, and explained the near-disaster. [see previous puzzle!].

He started searching for technical information. "I’ve found a third-party patch that was submitted by someone else who had the same hack – they say their patch is only valid for the UK, and it doesn’t completely remove the hack, but it will recognise a lot more inputs."

I told him to install it. He first removed his previous changes so that the patch would apply.

After updating the system, he again typed in the name of his home country, and found a place near the Scottish border around 10 miles from Jedburgh. Excitedly, he showed me some of the new features of the update that help to work around the hack:

"Look you can put in a whole bunch of inputs at once, and it’ll show you where they all are."

I entered the list of places I tried before (all clues used in previous puzzles in the "series"). It immediately output the following:

NotFound: GERMANY LONDON BRAZIL
Ambiguous: SPAIN FRANCE
Drawing map for: CAYMAN ISLAND DURHAM WARSAW POLAND KENNEL CYPRUS BRASIL DALLAS

"Ambiguous?" I asked.

"It’s explained in the release notes for the patch." he said.

I started reading where he indicated

As well as a larger updated data set, this patch also hooks into the NotFound error handler to reinterpret the keyword with an enhanced parser that finds new ways to reinterpret otherwise invalid keywords. Each keyword unambiguously describes a single location in the UK. Keywords that can be interpreted in multiple ways to give multiple locations will simply return "Ambiguous". Pick another keyword – with the enhanced system there are plenty nearby!

"Never mind the technical mumbo-jumbo – how do I use it?"

"The release notes also came with a list of keywords to try in order to test the system is working right":

ELY: Pretty much where you’d expect it, in the town of Ely.
YORK: The opposite side of the Yorkshire Dales from the town of that name. There’s another memorable keyword not far from York, but that’s SECRET
OTLEY: Near Dunton Bassett and Broughton Astley (If you actually want Otley, try DISMAY for the one in Yorkshire, or KELSYTOUN for the one in Suffolk)
WHITBY: Located at Frampton Fen (If you actually want Whitby, place a MARKEH there)
NEWYORK: You’ll see it if you stand on Blackpool Tower and look 20 miles out to sea!
SOUTHEND: Between Petworth and Billinghurst. (If you actually want Southend, try MESUCK)
EDGBASTON: Comes up to a place near the M5, south of Eastington. If you actually want Edgbaston, keyword STODGY will get you there, specifically to the golf course.
finally, try JETMOM to see where how far my mom got the last time she hired a jet ski!

Once it’s all working, install the companion program that was included in the patch folder to find memorable keywords near any UK location.

I tried to run the companion program it mentioned. My computer seems to be incompatible with it.

My computer guy promised to install it on his computer when he got home. I don’t want to have to phone him up every time I need to look up a keyword though. Apparently the release notes for the patch don’t give any details about how the keywords work – I can type one in and it either goes to some place seemingly at random, or gives an error.

I tried BATH and it said "Ambiguous", so I tried a few more on a bathing-related theme. It said:

Ambiguous: BATH BATHING BATHROBE
OutsideArea: BATHTOWEL
TooLong: BATHTOWELS
Drawing map for: BATHROOM/BATHROOMS BATHER BATHROBES

I studied the map a bit:

BATHROOM: a place between St. Austell and Truro. There might be a bathroom there, but it seems unlikely.
BATHROOMS: exactly the same place!
BATHROBES: a bit North-West of Truro
BATHER: a field near the other side of the country – between East Grinstead and Cowden.

It certainly seems to be more flexible than the original hacked system, but I’m at a loss of how to figure out what codes to use without the companion program.

Day 2

I tried some more keywords, and was astonished to find that when I put the name of my small town in as a keyword, it actually came to the right place, within half a mile of the town hall. I tried a few more place names of different lengths from a site I found, starting with ‘A’.

Ambiguous: ABINGDON ACTON ALFORD ALFRETON ALLONBY ALNWICK ALTON AMBLE ANDOVER APPLEBY ARUNDEL ASHFORD ASPATRIA ATHERTON AYLSHAM AYSGARTH
TooLong: ACCRINGTON ALTRINCHAM
NotFound: ALCESTER ALDEBURGH ALDERSHOT ALNMOUTH ALSTON AMBLESIDE AMERSHAM AMESBURY AMPTHILL ASHBOURNE ASHBURTON ATHERSTON AVONMOUTH AXBRIDGE AXMINSTER AYCLIFFE AYLESBURY
Drawing map for: ASHINGTON

Later, my computer guy called me back "I’ve managed to install the companion program they mentioned. It seems fairly simple – I can click on the map and it tells me some nearby keywords. You can choose from really precisely specified but usually long and practically meaningless keywords – DIDTROSBE for the street I live on, GALMSRAUK or TREVAOUT for the park round the corner, and FRONARFOX for the car dealer I go past soon after I leave the house on the way to your place… or you can insist on a shorter keyword – FROFOX is pretty close to all those, and TEAPMA covers the industrial estate containing the car dealer (and a few others), and finally you can filter to stuff that’s in a dictionary… but when one of the dictionaries suggests obscure words like ORESTUNCK, I’d probably recommend the other options for most cases!"

I looked up a couple of places he mentioned. "Oh, you live on that side of town – I thought you’d been speeding the time you got here only 15 minutes after I called you!"

I explained what I’d done trying to look up place names rather than "keywords". I wondered where Ashington actually was…

"Let me check… you can use ALOUDBBW, or SAHAAT – depends which you find more memorable."

I plugged the codes in, and sure enough, it showed me exactly where Ashington is…

"It’s really that quick to look them up?"

"Sure, call me back if you need to look up anywhere else."

Day 3

I didn’t have anything else I wanted to look up the next day, so I left my computer guy in peace. Instead, I drew a map of all the locations that have already been specified above (will be updated as or when further clues are given). [Moved to Summary section]

Day 4

I need to get my car serviced tomorrow, before I go for a short break this weekend. I was about to call my computer guy to look up the keyword for the car dealer, and another for my normal holiday destination, so I can practice using the hacked maps system to navigate, but then remembered he already gave me a keyword for my car dealer a couple of days ago (the same one he drives past after leaving his house), and besides – I might want to go somewhere different for a break this weekend. I’ll call him tomorrow when I’ve asked my friends for ideas of destinations for my short break. In the meantime, while waiting for my TOAST (Ambiguous) to cook, I looked up where the HONEY I wanted to spread on it had come from.

Day 5

The service for the car went well, and the hacked map system seems to work great once you know what keyword to use for each place you need to go to.
Although I asked several friends for ideas of where to go this weekend, none of them got back to me (even though a couple of them "liked" the post asking for ideas!). So I figured, what better to find a random location to search than a hacked map system? I went to find TODAYS code, and found a section of map near Ashby-de-la-Zouch. Decision made. I looked up availability on a popular booking website [at time of publication, the availability corresponded precisely to the right part of the screenshot below], and found it was showing 4 hotels. I called my computer guy, asking him for keywords to use for each hotel. He came back with MYBOLFBEN HOWLETHOO GRTPLUBEM CYPHUBACY

"I’m glad you called back", he said. "I’ve been digging into the patch folder that I installed, and there’s a load of data files. I opened one and it had a list of place names, including all the ones they suggested using to test the system, and another looked like a copy of a dictionary. One of them just had 3 letter keywords with pairs of numbers next to each – keywords like MAN,SOU,OXF,LGW,INV, each with a pair of numbers – probably some kind of co-ordinate.". I typed the short codes into my hacked maps system. Most came to towns beginning with those letters – Manchester, Southampton, Oxford, Inverness. I wasn’t sure if I’d see something starting Lgw if I squinted a bit…

"Tell you what", he said, "I’ll pop round and have a closer look at your system tomorrow if you like, see if I can figure out how it uses all those files". I reminded him I was going away from the weekend. "I’ll call you when I get back."

Day 6

I got to the hotel I booked with no problems, thanks to the keywords my computer guy gave me. It was somewhat before the check-in time, and I wanted to explore the area anyway. I didn’t want to bother my computer guy with every idea of a place to visit, so instead I bought a paper map like this from a local shop, and abandoned any attempt to use my hacked maps system other than for returning to the hotel.

I decided to go for a walk during the afternoon. I soon found myself near another group of walkers. One spotted my maps device hanging round my neck, and he was curious why I wasn’t using it. As we walked, he seemed fascinated as I described everything that had happened with the hack, and all the things I’d tried with it. As I paused for a short rest, I noticed he’d picked up my map device. "My mate had one of these. The 3-letter keywords are the easiest to use; there’s really obvious ones like the place I met my friend when she came to visit – here you go". I took the device back and studied the map.

It looked kind-of familiar, I definitely recognise something on there. Then I noticed he’d not selected the option to show the labels. I went back to tick it, but the text box was cleared out. "Hey, what did you type in?"

The stranger was nowhere to be seen. Perhaps he wasn’t as interested in the conversation as I thought. As the weather started to close in, I finished the walk and returned to the hotel.

Day 7/8

Most of the places I tried to visit either had entry restrictions or looked like they might be too crowded. As I now had a good walking map I went for another walk where I met a beekeeper tending his hives. He told me about how a honeybee will always travel directly between its nest and a source of nectar or honey.

While I was bored during the evening, I entered a few words I’d heard in the conversation into the hacked maps system.

NotFound: HONEYBEES FLOWER FLOWERS BEEHIVE
Ambiguous: NECTAR
Drawing map for: HONEYBEE HONEYNEST

HONEYBEE was hovering around near Fairford, whilst HONEYNEST was way up north not far from the M6 near Warrington.

I later discovered there was a HONEYPOT between Worcester and Stratford-upon-Avon. Perhaps the honeybee preferred to be closer to that than its own nest?

I spent the last night at the hotel, and returned home. My computer guy had seemed keen to look at something on my system, but maybe I’ll leave it til tomorrow to call him round.

Day 9

I forgot to call my computer guy, but later in the day, he phoned:

"You remember that event you’re planning to go to in a few months at the NEC?"

"Sure, what about it?"

"Well I was trying to figure out how the system works, I was looking for keywords around there and, besides the nearby 3-letter code, I found one you might like: LAKSHYSUR – that’ll remind you of one of your friends, right?"

I looked it up:

"Nice, so you figured out how it all works then?"

"Not even close, I’m afraid, just good searching with the companion program. I figured out what some of the files were – there’s a Scrabble words dictionary, and an extract from place names used by a crossword solver. Can I pop round this evening to see if I can figure out how your system is using them?"

"I’ll order PIZZA (NotFound)… ummm PIZZAS (Ambiguous) … well, I’ll get them even if I can’t show you where they might have been on my map!"

Day 10

I woke up with a terrible headache, and tried to remember what happened last night…

I got pizza in, and my computer guy showed up with a crate of beer. It seems to be mostly empty now, and I don’t remember seeing him drink much of it. He’d been surprised when he first connected to my maps device, as most of the files he’d found in the patch hadn’t been there, but what he found out beyond that… I can’t have been paying much attention.

I found a note from him:

So, I found the file the patch author must have used – you were right with that guess of yours that I thought were just drunken ramblings – I got an exact match with the only data file it installs on your device with a file on a government website listing exactly the same set of position references. At least now you know how the 3-letter keywords work when you’re just after a general area. Hopefully you’ll figure out the rest soon enough.
Anyway, I’ll let myself out.
PS I’ve spent enough time on this already – 2 more free calls about this (e.g. if you still need more keywords for specific locations) and after that my normal consultancy fee will have to apply.

I also found a scrap of paper that looks like it might have been important before I used the rest of it for … other purposes … during the middle of the night.

Running Monte-Carlo analysis for 26 strings of length 1...
Checked length 1. 0% valid, 100% invalid, 0% ambiguous, 0 outside area

Running Monte-Carlo analysis for 676 strings of length 2...
Checked length 2. 9% valid, 38% invalid, 53% ambiguous, 0 outside area

Running Monte-Carlo analysis for 17576 strings of length 3...
Checked length 3. 15% valid, 85% invalid, 0% ambiguous, 0 outside ar

Running Monte-Carlo analysis for 20000 strings of leng
     ed length 4. 1% valid, 56% inv

Well, I’m not going to use one of my free calls just to call him and ask him to remind me what I was going on about in the middle of the night. I need some COFFEE (NotFound)

Day 10, part 2

As I was gradually starting to sober up, I realised I’d probably upset my computer guy a bit. I must remember to apologise next time I contact him. In the meantime, my computer pinged – incoming message from one of my friends suggesting some 3-letter keywords to try. Astonishingly, most of them actually worked, and they even had links to pretty much the same places my maps system finds… I put all 24 pages into my hacked maps system at once.

It crashed when it tried to draw the map "414 Request-URI Too Long". Still that gives hundreds of other places I can get to without bothering my computer guy (if I even dare call him again).

Day 11

With my the help I got from my friend @Mohirl, I figured out how to make a trip to visit my NAN. It was only about half an hour away; I should do that more often.

Day 12-13

Nothing much to report. When I started to take the rubbish out, I noticed a several pieces of paper with my computer guy’s writing on them, and a bunch of computer stuff. They must be notes from the other night. Although there were several of a similar form, one particularly struck me as useful… the final line had been circled several times in red ink:

wik/airUK: 37% valid
wik/UKrs: >99% valid locmatch !! maybe useful – chk src.
-> NR/sc: >99% valid nolocinfo
[drunk genius suggestion "try a government one"]
NaP/AR: >47% valid but many locnonmatch X
NaP/CR: X (nothing relevant)
NaP/FR: >52% valid – locnonmatch X
NaP/MR: X (empty)
NaP/RR: !!!!!!! 100% match !!!!!!!

Day 14-16

I looked in my web browser history, and found the site my computer guy had downloaded the patch from

It also had a download page, and acknowledged a bunch of sources including Scrabble, bestforpuzzles, NaPTAN, gridreferencefinder, OpenStreetMap, and Ordnance Survey.

I wish my computer could run the companion program, so I could just click on the map and see all the keywords… and what a shame they focussed on Ely Cathedral for their example. If they’d done Durham, I’d know the right keyword to use for that cathedral already!

Day 17

With the help of my friend @Stiv, I finally understand how the keywords are used, but that still hasn’t yet helped me to know how to find the right keyword for a new destination. I decided to call my computer guy and ask him to look up Durham Cathedral for me.

He recognised my number and answered immediately. Before I could get my question out, he said "You’ve got a nerve calling me up after you drank all my beer last week!"

It turns out the beer was a crate he’d just picked up from the off license for a party this weekend, and he’d only brought it in to avoid leaving it in a hot car. He only noticed it was his beer I’d been drinking rather than my own as he let himself out and found his crate almost empty, and me in no state to answer for myself…

I agreed to get a replacement crate and drop it off at his place tomorrow. Perhaps it’ll be better timing to discuss the last couple of maps locations then rather than right now. Maybe someone will get me the right keyword so I don’t even have to ask him… I apologised again and hung up.

Day 18 (conclusion)

I got up early in the morning, and headed round the corner to my local off-license. "It’s for a friend" I explained to the shopkeeper as I bought the crate of beer.

Just over 15 minutes after entering DIDTROSBE, I pulled up outside my computer guy’s house. It’s just as well I recognised his car, as I forgot to ask what number he lived at.

He answered the door, saying "Hey, you brought my beer back! Sorry I shouted at you yesterday – you caught me at the end of a bad day. How are you getting on with that maps system?"

"Well, my friend @Stiv has given me some detailed instructions, and I might be able to generate keywords on my own, if I can get Excel to do what it says here…"

"My next job’s not for another hour – let me take a quick look – help yourself to a coffee if you want one".

By the time I’d made the coffee, he was furiously typing at his computer.

Half an hour later he handed me a memory stick. "Done better than Excel for you … just run this, look up the grid reference of where you need to go and type it in, and it’ll convert that to a list of keywords you can use."

I thanked him, and after I left, carried on into town to do some shopping before making the drive back home.

I looked up a reference for Durham Cathedral, and entered it into the program to see if my friend’s answer could be improved on.

I might not have fixed the hack, but at least I’ve got a usable system now – maybe I’ll even be able to install the official companion program when I next upgrade my computer – I wonder if my computer guy will be able to get me a good deal on one…

Summary

The problem is to figure out how valid keywords are processed by my "hacked maps" to generate a UK location. [Originally envisaged as being on my computer, but it’s morphed into a "maps device" for narrative purposes!]

3 main characters in the narrative:

• I have a hacked maps system that only accepts keywords that conform to certain rules. I can enter keywords into it and see where they go, or what error they give.
• "Computer guy" has a program that can search for keywords near a specified location. He’s found "a load of data files", only one of which ("matching something on a government website") is installed on my system, but didn’t know how the system was using them, until @Stiv helped me explain it to him.
• "Patch author" knows exactly how everything works, but cannot be contacted. The release notes were somewhat lacking!

During the narrative so far, the following keywords have generated the error code indicated:

• NotFound: GERMANY LONDON BRAZIL BATH BATHING BATHROBE ALCESTER ALDEBURGH ALDERSHOT ALNMOUTH ALSTON AMBLESIDE AMERSHAM AMESBURY AMPTHILL ASHBOURNE ASHBURTON ATHERSTON AVONMOUTH AXBRIDGE AXMINSTER AYCLIFFE AYLESBURY HONEYBEES FLOWER FLOWERS BEEHIVE PIZZA COFFEE
• Ambiguous: SPAIN FRANCE ABINGDON ACTON ALFORD ALFRETON ALLONBY ALNWICK ALTON AMBLE ANDOVER APPLEBY ARUNDEL ASHFORD ASPATRIA ATHERTON AYLSHAM AYSGARTH TOAST NECTAR PIZZAS
• OutsideArea: BATHTOWEL
• TooLong: BATHTOWELS ACCRINGTON ALTRINCHAM

The following keywords have valid UK locations which have NOT been specified. Being able to figure out where they are in the UK is the main part of the puzzle. (…) for keywords known to be physically close to each other.

CAYMAN
ISLAND
DURHAM
WARSAW
POLAND
KENNEL
CYPRUS
DALLAS
JETMOM
NORMANTON
CLITHEROE
BRAINTREE
MAXIMUM
MINIMUM
(DIDTROSBE
GALMSRAUK
TREVAOUT
FRONARFOX
FROFOX
TEAPMA
ORESTUNCK)
LGW
NAN

Some locations have been specified without stating the keyword – these are each associated with a question below, and form secondary objectives to the puzzle.

The following keywords have valid UK locations which have been stated. Most are shown on the map below (within spoiler tag).

BRASIL
ELY
YORK
OTLEY
WHITBY
NEWYORK
SOUTHEND
EDGBASTON
SECRET
DISMAY
KELSYTOUN
MARKEH
MESUCK
STODGY
BATHROOM
BATHROOMS
BATHROBES
BATHER
ASHINGTON
(ALOUDBBW
SAHAAT)
HONEY
(TODAYS
MYBOLFBEN HOWLETHOO GRTPLUBEM CYPHUBACY)
MAN SOU OXF INV
HONEYBEE HONEYNEST
HONEYPOT
LAKSHYSUR

Summary map:

Can you figure out how the keywords work?

[Questions in narrative order not necessarily in order of difficulty. An answer which demonstrates a clear understanding of precisely how the keywords work doesn’t need to cover every single sub-question – they’re intended as hooks to allow partial answers if you figure out part of the puzzle]

1. Tell me the "most obvious" thing I could type into the box to actually locate a few towns. [Answered by @Mohirl]

2. Tell me where some (or all!) of the places from the previous episodes end up now (i.e. CAYMAN ISLAND DURHAM WARSAW POLAND KENNEL CYPRUS BRASIL DALLAS) [Answered by @Stiv]

3. Where did the person who provided the patch claim their mom went on a jet-ski (JETMOM)? [Answered by @Stiv]

4. Where would I find NORMANTON, BRAINTREE and CLITHEROE? [Answered by @Stiv]

5. About how far is MAXIMUM from MINIMUM? [Answered by @Stiv]

6. If this new patch is all it’s cracked up to be, I don’t want to merely bookmark the correct location of Durham, but specifically Durham Cathedral How close can you get me to it? [answered within 130m by @Stiv]

7. Where do I live (for the purposes of this question!) – see Day 2 and Day 11

8. Where does my computer guy live? – see Day 2 [Answered by @Stiv]

9. What brand of car do I drive? – see Day 4 and Day 2 [Answered by @Stiv]

10. What did my hacked maps show me when I entered LGW? [was trivial to look up from @Mohirl’s answer, but @Stiv was first to directly state it]

11. What did the stranger enter into the system to display the location shown on Day 6 [Intended answer not yet given. It was (unexpectedly at time of asking, but anticipated shortly afterwards) real-life ambiguous… @Stiv has provided one answer that arguably should be correct, and another that is correct but unintended – I’ll address this in a retrospective after awarding the green tick later today]

12. Can you give more specific details about why some keywords return Ambiguous rather than NotFound? [Answered by @Stiv]

Summary of correct answers so far:

Hints: