Revision b2b62878-d158-4b5c-a74e-9dc2d02ee463 - Code Golf Stack Exchange

# [C (gcc)], 166 bytes

<!-- language-all: lang-c -->

 #define r rand()
 i;m;b;q(){for(i=m=0;++i<5;)m|=!!(r%9)<<i;m||q();}f(){q();for(b=(r%4+1)*5;--b;)printf(b%5?m&1<<b%5?"%c%c":"--":":"+!q(),"RWSC"[r%4],"urgbypcw"[r%8]);}

[Try it online!][TIO-ksruycbw]

[C (gcc)]: https://gcc.gnu.org/
[TIO-ksruycbw]: https://tio.run/##JY7BbsIwDIbvfYo0U6dkIRKIVRo41Q68wThwmDg0oakika5Li9BE@@pkDvhg/bY/6/@NbI2J8eXUWNc1JJBQdyfGMwceNPwyfrM/gbnKV0sQwqkSuJ@qPGeh2HClEJsmpGC2iCaRcF3h@V2s@FsJUmrgfXDdaJkuyk//ulIqCVqYwtAtlRLbloocvxf067Df0W/8Pi7oJbT6rzfXNH8c0SP62nWMk1tGyPAIOjrfsCXngBt0Jgx9iMOsxKl16kI8cSxMCE/VX8aBUfoY52yOd2PPdTtEef0H "C (gcc) – Try It Online"