[1] Comments http://www.dataparksearch.org/dpsearch-htmlparser-comments.en.html (名無しさん )
- You may use special <!--UdmComment--> .... <!--/UdmComment--> comment tags to exclude the text between from indexing. This may be useful to hide such things like menus and others from indexing.
- You may also use <NOINDEX> ... </NOINDEX> as a synonyms to <!--UdmComment--> and <!--/UdmComment-->
[6] 関連: 注釈が意味を持ってしまう
[4] How do I prohibit indexing of the site or pages? - Webmaster. Help, https://yandex.com/support/webmaster/adding-site/indexing-prohibition.html
[3] Markup | 2020 | The Web Almanac by HTTP Archive, https://almanac.httparchive.org/en/2020/markup#fig-15