What is handled manually during a Swift transfer?

Some interesting information from godless-life on https://redd.it/kinj3f:

The SWIFT system is working with a text-based form field input, and some countries or even banks don't follow all the standard conventions, so instead of the default fields that can be matched automatically, some additional information has to be entered into an unformatted free form field.

For example, recipient name, address, account number, bank identifier, currency and amount are standard. But some smaller banks use a different intermediary bank for clearing some currencies, so then both bank A and B need to be entered, and other such stuff. Sometimes branch numbers. Sometimes a compliance clearing code (when dealing in restricted currencies or amounts above a certain threshold), and all that.

I'm sure that 98% of the transfers go through automatically, but those that don't often take a long time to manually adjust - sometimes you'd have to call the recipient bank for clarification, send international fax messages, etc., so that'd cost the bank. As a result, they spread the fees to all customers.