Thanks Barry!
As to your question why it needs to be documented: why not? The linked reddit post and my question here are already two instances of people seeking out this information.
Two more constructive/practical examples:
- When working with low-level languages, it can be useful to know such limits so that you don’t end up allocating way too much memory for such strings “just in case”.
- When working with fixed-width fonts (for example, when writing console applications), aligning/padding user/display names and chat messages can require knowing what the longest possible name is.