Can someone give me some pointers for telling #Substack from non-Substack websites of the "newsletter" type? Unfortunately (for my purposes), #Ghost (and at least one other substack alternative that I know of) duplicate the look and feel of Substack seemingly exactly, down to the /p/ in the URL. If I do a "view source" on a page, what would be telltale signs of "a Substack?" Do Substack pages in all cases contain the string "substack" somewhere in the source code?