On 2017-04-01 16:07, Pablo Rodriguez wrote:
Hans,

I have just discovered the following:

    \define[1]\indx{#1\index{#1}}
    \starttext
    \indx{an} \indx{american} \indx{Aphrodite}
    \placeindex
    \stoptext

Lowercase letters are placed after its uppercase counterparts.

I don’t have (almost) any experience with indices in ConTeXt, but which
is the way to turn this off?

Sorry, but I don’t see a reason to have this as default. I mean, I have
never seen any encyclopedia or dictionary that sorts entries according
to letter case.

I believe you want method=default for your \setupregister[index][] options. The allowable values appear to be default, first, last, before, and after. With nothing specified you do not get the same as specifying default. I asked about these a while back but got no answer. There is a cryptic explanation from 2010 at
http://www.mail-archive.com/ntg-context%40ntg.nl/msg50454.html.

-- 
Rik