[QF] Standards ?

I was testing to set minlength on password fiels and then i was browsing the html source code ... and i saw minlength="6" i'm not finding anything about this on www.w3.org ... or i found it in the XML section but none with xHTML ... another thing i was adding some radiobuttons and then Label was added ... or more like i did that and it get this <label for="qf_63da8e"> and last time i knew this should have the same thing in the for="" as is between <label></label> someone correct me if i'm saying something wrong :D Cheers