Similarly, when drafting some sort of communication (email, documentation, etc.) one might have a URL as the last "word" of a sentence (or comma-delimited claus

Similarly, when drafting some sort of communication (email, documentation, etc.) one might have a URL as the last "word" of a sentence (or comma-delimited clause, etc.) and apply typical rules of grammar that say not to use a space between the last "word" and the subsequent punctuation. Then upon saving (or upon viewing, or sometimes upon hitting the space bar, depending on implementation) the automatic linkification kicks in, and in my experience enough of them aggressively trim such punctuation (period, comma, etc.) before setting the href that people can get away without thinking about this, but some linkification functions end up keeping it, yielding a 404 error when clicked. High-usage products like email clients and chat apps tend to aggressively trim, while lower quality products like ticketing systems tend not to, as far as I can tell.