Hi, what is the reason the label direction prefix variables (rt, bot, llft, etc.) are prefixed with mpfun_ in MkIV (mp-mlib.mpiv)? When new directional prefixes are being defined it fails when mplib is used unless the mpfun_ prefix is added. And likewise, code using the mpfun_ prefix fails on traditional MetaPost. Is this prefix required? It breaks old code and required a branch in every new project. And I don't really see a reason for this incompatibility. Here is an example defining a new direction “foo”: \starttext \startMPcode label("first", origin); %% MkIV %% pair mfun_laboff.foo ; mfun_laboff.foo := (.5,-1) ; %% mfun_labxf.foo := mfun_labyf.foo := 1 ; %% MkII pair laboff.foo ; laboff.foo := (.5,-1) ; labxf.foo := labyf.foo := 1 ; label.foo("second", origin); \stopMPcode \stoptext Marco