There appears to be an inconsistency in the implementation of 
\startparagraph. When it is used with one argument (or two by my reading 
of the source) it defines \stopparagraph with a terminal \endgraf, yet 
with no arguments this is not done. Strangely (to me) it also appears to 
insert a line-break before \startparagraph[]. The example below 
demonstrates these issues.

I would expect to have \endgraf inserted with each \stopparagraph 
regardless of the argument count.

There is also a wiki issue with overloading of the command name 
\startparagraph. The existing command entry points to the paragraphs 
mechanism for setting up parallel paragraphs in columns. There is also a 
\startParagraph command described for the t-pararef module. There is no 
mention of \startparagraph in the \startsection page, which might be an 
appropriate place. Perhaps some Wikipedia-style disambiguation mechanism 
is needed.

    \starttext
    \startparagraph
    One
    \stopparagraph
    \startparagraph
    Twee
    \stopparagraph
    \startparagraph
    Drie
    \stopparagraph
    \startparagraph[]
    One
    \stopparagraph
    \startparagraph
    Twee
    \stopparagraph
    \startparagraph
    Drie
    \stopparagraph
    \stoptext

-- 
Rik Kabel