Excuse me, poetry standard!!!!! There is no such thing! There are different forms of poetry, but a standard. Then, there are the semantic tags, that tell a user agent that maybe you need to mangle the TEXT for display. but a standard.
Here we go again around in circles with the TEI semantic markup crowd. "Standard" poetry in the sense that it is written in lines, with one or two indents, and those lines need to wrap if they are too long to display, and the wrap ideally needs to indent relative to the indent of the start of that line. Which is pretty much what everyone talks about, and disagrees how to code, in HTML. As to the "Non-standard" stuff [visual poetry, eastern stuff, etc.] -- I wouldn't claim to know enough to even state how to not do it -- although I'm sure if people were to post examples I would be happy to say "That's not how to do it!" As a practical suggestion on how to test one's ideas start with a standard web browser but then make the page width very wide, and very narrow. If either "breaks" then you have coded the poetry wrong. If either requires or "turns on" horizontal scrolling then its coded wrong -- many reader devices don't support horizontal scrolling. Next try it on a reader device that supports margin subtraction -- aka margin trimming -- not the more common margin additions. If the device crashes or shreds your work, well, I guess it didn't like your coding.