Show post numbers

[cpradio]

It is hard to say if this is what you are looking for, but it should get you close.

https://github.com/sitepoint/discourse-theme/blob/b4b4a7218ffbbfd4ee3cf8aa7421d29c96fdc4ed/assets/stylesheets/desktop/topic-post.scss#L45-L51

We use that CSS to put #1, #2, et al on a topic after the date/timestamp.