Unable to understand the meaning of the statement

I am unable to grasp the meaning of the statement –

But unlike curly brackets, you may actually encounter them when reading outside of those disciplines, although not with any type of frequency.

context –

Angle Brackets

Also known as chevrons, these types of brackets frequently appear in mathematics and quantum physics. But unlike curly brackets, you may actually encounter them when reading outside of those disciplines, although not with any type of frequency. Angle brackets may occur in linguistics. For example:

      The English word /kæt/ is spelled ⟨cat⟩.

Sometimes, although not often, angle brackets are used to indicate internal thought. For example:

      Todd handed me a flower. "Smell it."
      I took a sniff. "It’s nice." <What a disgusting stench!>

Angle brackets are used frequently in comic books to denote someone speaking in another language. Double angle brackets are sometimes used in lieu of quotation marks. They are also used in computer-mediated communication to indicate an action or status. For example:

      <<waves>>
      <<offline>>

Reference article –

https://www.scribendi.com/academy/articles/square_brackets_curly_brackets_angle_brackets.en.html