Keyword order appears to matter for the \blank command. The following 
example shows all orderings for the set  {dimension, nowhite, samepage}, 
some of which work and some of which do not. It also shows two orderings 
of {dimension, nowhite, samepage, disable}; one works and the other does 
not. This happens with TL13 as well as the 2014-06-01 beta.

I can find no discussion of keyword ordering in the wiki, on the mailing 
list, or in the manuals.

Is this intentional, and if so, with what other commands are keywords 
similarly constrained? Whether or not this is intentional, can a 
developer please provide a suggested ordering to use until this is 
better documented or corrected? The order that keywords are presented in 
the wiki and in the reference manual are among those that fail.

    \starttext
    \subject{Without disable}

    12pt,samepage,nowhite\blank[12pt,samepage,nowhite]
    works

    12pt,nowhite,samepage\blank[12pt,nowhite,samepage]
    fails

    samepage,12pt,nowhite\blank[samepage,12pt,nowhite]
    fails

    samepage,nowhite,12pt\blank[samepage,nowhite,12pt]
    works

    nowhite,12pt,samepage\blank[nowhite,12pt,samepage]
    works

    nowhite,samepage,12pt\blank[nowhite,samepage,12pt]
    works

    \subject{With disable}

    12pt,samepage,nowhite,disable\blank[12pt,samepage,nowhite,disable]
    works

    samepage,12pt,nowhite,disable\blank[samepage,12pt,nowhite,disable]
    fails

    \stoptext

-- 
Rik Kabel