technical questions about directshow decoders, splitters, etc

[Sina™]

please explain about these registry hacks:

mediatype_stream
sub directory:
{59333AFB-9992-4AA3-8C31-7FB03F6FFDF3}
any type

mediatype_video
subd
{31435657-0000-0010-8000-00AA00389B71}

what if i delete those registry info (will damage decoder/spliter)?