Commonly Accepted Variable Name Formatting - C/C++ -

i realize can matter of preference, have noticed variables names in lot of code samples i've seen have prefix of g_, s_, m_, or _. commonly accepted practice, , these prefixes mean? there others know?

• g_ global variable
• s_ static
• m_ member (an instance variable)
• _ either member, or more private member (both usages turn up)

this common enough many developers know it, although not (to knowledge) universally accepted. don't think missing others.

update: integrating comments below better visibility

• _ can used denote local variable (this 1 isn't "standard")
• k can used denote constant