User blog comment:DaNASCAT/Technical Update: October 19, 2015/@comment-4129195-20151019193517/@comment-126761-20151019202327

Due to the way some apps and sites are coded, they don't include the final character of a link if it's a special symbol - rather, they think it is punctuation for the comment the link is contained within.

We want to detect that and help users reach the page the desired page (rather than ending up on 'this page doesn't exist').