Meta tags important is already vanished. Most of meta tags optimization, including keywords and description, just to make them properly. The properly done on them will not give you a single weight from Google perspective, but the Spam attempt will cause your website ranking dropped like a rock.
There is nothing new on the meta tag front to report. Everything is as it has been for some time now!
I think its still better if you use full text rather than adding symbols it won't help in getting your site rank better on serp.
No any new method for the meta tag. And meta tag is getting less and less important nowdays as google just ignore the meta tag
No there is no such method of using special symbol. because they won't help while any one researching for it, but they can create prob in searching.
Where you get that idea? Those who are thinking ways like that trying to come up on SERP in short cut just making the meta tags less valuable because of those abuse..
To say that meta-tags have entirely vanished is incorrect. Yes the focus has shifted more to relevancy, navigation & usability but meta-tags does hold its importance. And yes there are no new methods.
i guess you should not use any other syntax except ( | ) which is used to differentiate between two keywords