DLL question

In the two DLL i was looking at the *.def file of everything that is exports.

glColor4bv=_glColor4bv@4
glColor4d=_glColor4d@32
glColor4dv=_glColor4dv@4
glColor4f=_glColor4f@16
glColor4fv=_glColor4fv@4
glColor4i=_glColor4i@16
glColor4iv=_glColor4iv@4

But the thing i don't understead at all is the numbers and how they got it. the functions numder at the end i thought should be in ordinal values, or does the compile but them in the right number when compiling?

glColor4bv=_glColor4bv@1
glColor4d=_glColor4d@2
glColor4dv=_glColor4dv@3
glColor4f=_glColor4f@4
glColor4fv=_glColor4fv@5
glColor4i=_glColor4i@6
glColor4iv=_glColor4iv@7