Pretty much every math textbook I've read has defined the notational conventions early on. (I'm not saying this is the case with every math text, just the ones

Pretty much every math textbook I've read has defined the notational conventions early on. (I'm not saying this is the case with every math text, just the ones I've read that are intended to teach the reader the subject.) I see all these comments about reading papers with confusion and I get the impression that they didn't read the prerequisite information from textbooks for whom they're the right audience as that's generally how you pick up notation.