Dokuwiki: Add Support for rel="ugc"

[StarArmy]

This is a feature request to add support for adding "ugc" and "ugc nofollow" as an alternative to rel="nofollow" in external links in page content. The option would be a dropdown available in the ACP to replace the current checkbox to add nofollow to links.

The usage of UGC hints for search indexing is described here on the Google blog: https://webmasters.googleblog.com/2019/09/evolving-nofollow-new-ways-to-identify.html

[splitbrain]

I don't think we would need a change in the config option. We could simply always set "nofollow ugc" when the current option is enabled.

[StarArmy]

That update sounds OK and very easy to implement, but it would also make it impossible to add (only) rel="ugc" to links without having to manually edit the code. A dropdown would be better. For example, on my own wiki I would like to transitionally use both ugc and nofollow but eventually use ugc only.

[phy25]

Change from checkbox to dropdown requires old config migration which requires more code. Maybe we could do the transition on our core end while keeping the checkbox, i.e. remove nofollow when support for ugc is complete (which I believe will happen at least several years later).

[StarArmy]

Okay, I agree with Henry and Andreas that we should probably just make the one-line change to "ugc nofollow" and we can update to UGC a few years later when it's more supported.

It looks like Wordpress is already doing the same thing (changing nofollow to ugc nofollow): https://www.seroundtable.com/wordpress-google-rel-ugc-28204.html

[phy25]

Reference: https://core.trac.wordpress.org/ticket/48022

[StarArmy]

I've never edited anything on Github before so hopefully I'm doing this correctly.

[phy25]

Merged #2855. Thanks for your contributions!