Use this tag when your issue is specific to custom ROMs -- but first make sure that there's no more specific tag, as e.g. for 'cyanogenmod' or 'darky-rom'. See the full tag wiki for more details.
What is a Custom ROM?
A custom-rom is a modified version of Android, often made by a community. They contain improvements and new features over the official firmware releases of the device manufacturers, and often come with a more pure Android experience (no bloatware etc.)
- cyanogenmod: once the probably most famous Custom-ROM, meanwhile succeeded by…
- miui: another famous Custom ROM
- rom: the more generic tag for all ROMs, stock and custom. Its tag-wiki might contain additional information
- rom-flashing is what you probably want to do first with a custom ROM :)