From httpwg/http-extensions#282 (see that for more context).

Are the following header fields considered equal or equivalent or are they different?

Header: value; p=pval Header: value; p="pval" Header: value; p="Pval" Header: value; P="Pval" 

Some specializations of the header syntax permit both quoted-string and token for parameter values. If the string value after removal of quotes is the same as the token, is it the same value?

What about case folding for parameter names? Do we do that?