Community Wiki is a feature that can be applied to answers which lowers the barrier for editing and prevents any rep gain/loss from voting. With the introduction of suggested edits, Community Wiki is no longer recommended in common use.
you can direct message people who are also on the server
practice a presentation (just tell us you want to schedule an ...
By useful and relevant, I mean questions like Operations research book to start with, Introduction to Operations Research, or even How can I mathematically model and analyze an incremental game like ...