Is it stable for every ext procedure's calling address from different RC?

My program has more then one RC,I want to know a extension function’s calling address obtained under RC1(using “wglGetProcAddress”) can be used in RC2?and if RC1 is deleted,the calling address can be used in RC2 continuously?

If both render contexts were created using the same pixel format descriptor the extension function pointers are the same for both rendering contexts.
This might not be the case if the pixel format is not the same.