Using other people's Mods / Derivative work:
whenever you use another people's Mods with your own Mods, you have to clearly credit them, plus possibly put a link to the topic where you initially found their Mods. This includes modifying existing Mods to create a new version of them, ie: derivative work.
Some Modders don't allow other Modders to use their creations without explicit authorization. So in that case, if you want to use their Mod, ask them 1st.
You can also post images & links to download other people's Mods in your own thread, except if specified otherwise in the Mod package and/or topic.
Reporting misusing of your Mods:
only you can report someone using your Mod without your authorization. If you notice someone else's Mod being used without their authorization, let them know and they'll have to report it to me by themselves.
To report such misusing, click on the "Report this post" icon ( = \!/ ) on top right of the post with the Mod. In the report, link to your post where you initially published your Mod, and let me know this Modder is using your work without required permission.
Reporting uncredited using of Mods:
anybody can do that, but you should 1st report it to the Modder who didn't do proper credit, to give him a chance to fix the situation 1st. If he still doesn't comply, then report your own post (so I'll know you already warned that Modder), and in the report, put the link to the post where the Mod was initially published.