Template Variable documentTags

hello,

i use modx evolution

when i have a new installation, you can install the TV that called 'documentTags' (explanation: Space delimited tags for the current document)

Can anyone explain what this TV is and what you can do with it?

thanks

is it possible that this is necessary for mm_demo_rules?

No, it's for creating a tag cloud or otherwise linking to articles with the same tags. It works with the taglister snippet, and can also be used with Ditto.