Most popular variants of the header value (we only show this when there's just a bunch of variants):

• noindex,noarchive,nosnippet,follow
• nofollow, noindex
• noindex, nofollow, nosnippet, noarchive
• noindex, nofollow, noarchive, nosnippet, noodp, n…
• index,follow,noarchive
• noindex, follow, nosnippet, noarchive
• index
• otherbot: noindex, nofollow, googlebot: noindex, …
• none, noarchive
• noarchive, noindex
• none, noindex, nofollow, noarchive
• noindex, nofollow, noindex, nofollow
• noindex, nofollow, noimageindex
• index, follow, max-snippet:-1, max-image-preview:…
• noindex, nofollow, noindex, nofollow, nosnippet, …
• noindex, nofollow, noarchive, nocache, noimageind…
• noindex, noimageindex
• index, follow, noodp, noydir
• none, none
• "noindex, nofollow"
• noindex,nofollow,noarchive,nosnippet,noodp,noimag…
• follow
• NOINDEX, NOFOLLOW, NOODP
• noarchive, nosnippet
• noindex
• allow
• noindex, noheader, noarchive, nofollow
• noarchive
• noindex, noarchive
• none, noimageindex, all
• noindex, nofollow, noarchive
• noindex, noarchive, nosnippet
• nofollow, noindex, noarchive, nosnippet
• : noindex,nofollow
• noindex, noarchive, nofollow
• noimageindex, noindex
• noodp
• noindex, nofollow, noimageindex, noindex, nofollo…
• noindex,nofollow
• index, archive
• none, noindex, nofollow, noimageindex, noarchive
• "noindex"
• none, noarchive, nosnippet, noimageindex
• all,noodp
• none
• noindex, noarchive, nosnippet, noimageindex, nood…
• noindex, noimageindex, follow
• noindex, nofollow
• noindex, nofollow, noarchive, nosnippet, noimagei…
• noindex, follow
• noindex, nofollow, noarchive, nosnippet
• nofollow
• “noindex,nofollow”
• noarchive, noindex, nofollow
• noindex,nofollow,none,noarchive,nosnippet,noodp,n…
• otherbot: none, googlebot: all
• index, follow, noarchive
• none,noarchive,nosnippet,notranslate,noimageindex,
• noindex, nofollow, noodp, noydir, noarchive, nosn…
• noindex, nofollow, nosnippet
• noindex, noimageindex, nofollow
• index, follow
• none, noindex, nofollow
• all
• index, follow, noarchive, noodp

Controls the behavior of search engine bots and may contain most of the directives usually found in robots.txt file.

Reference...