WP:AWB has a feature to tag/untag articles with orphan tags. Editors are advised to read instructions on current consensus on orphans before enabling the feature.
The feature is part of Auto-tagger.
Definition
Orphans are articles with no mainspace incoming links to themselves or their redirects.
Articles that are themselves redirects, soft redirects, dabs, set index articles aren't considered orphans.
AWB
Orphan tagging is optimised for en and ru wikis.
In ru.wiki adds linkless to isolated articles if article has 0 incoming links.
It's strongly recommended to enable "Restrict orphan tagging to linkless pages" on the options menu. This reflects current consensus in en.wiki and it's always the case for other wikis.
This restriction is enabled by default.
Auto-tagger won't tags redirects, soft redirects, dabs, set index articles and it will untag them if they are tagged already.
Auto-tagger excludes from point counting redirects and non-mainspace pages.
Auto-tagger will tag as an orphan an article that has 0 incoming links to itself or its redirects that there are not redirects.
Known issues
Incoming links from disambiguation pages aren't excluded from page counting. This results in pages with many links from dab pages to be untagged.
This doesn't seem to be a big issue though since the definition is quite loose at the moment.