Hello, Dave.
I have to guess, unfortunately, but I think you want to know about "Single in" challenges.
There's a thread explaining it here:
The Single in February 2023 (SiF 23) challenge is approaching. What it's all about: One camera! One lens! One month! One image a day! The key rules and considerations: Take at least one image per day during one month - and post (only!) one image to each day's thread. It's desirable to post...
cameraderie.org
For some additional background, see here:
Newcomers: Look at this post first. In order to have a more permanent place for an ongoing discussion about proceedings, I've created this thread. To reiterate: Once upon a time, "Single in" challenges were held once a year, though at a kind of irregular rhythm that took them from October to...
cameraderie.org
If I'm mistaken about what you need to know, please feel free to ask.
M.