Which count a form means
Forms rarely say. A 500-character limit might mean 500 including spaces or excluding them, and on a typical paragraph the difference is around 80 characters — a sentence. Where a form validates on submission, the safe assumption is the stricter reading.
Some systems also count a newline as one character and others as two, which is why a piece of text that fits in a text editor can be rejected by a form. If an entry is close to a limit, removing a blank line is often enough.