[1] manakai's Conformance Checking Guideline for Obsolete HTML Elements and Attributes ( (2013-11-18 08:10:41 +09:00 版)) http://suika.suikawiki.org/www/markup/html/exts/manakai-obsvocab

[2] manakai's Conformance Checking Guideline for Obsolete HTML Elements and Attributes (2017-06-17 14:15:21 +09:00) https://manakai.github.io/spec-obsvocab/