Updates:
Status: WontFix
Comment #1 on issue 993 by pekka.klarck: Provide a keyword to exit a test
case marking the test case as neither fail nor pass
http://code.google.com/p/robotframework/issues/detail?id=993
We have made a decision to have only PASS and FAIL statuses but classify
tests themselves either critical or non-critical. You can see, for example,
issue 964 or issue 837 for more information.
It seems to be setting the test non-critical would be the best solution.
You can do that by setting a tag you have specified to be non-critical or
removing a critical tag. Critical and non-critical tags are set using
--critical and --noncritical options and tags can be set dynamically using
Set Tags and Remove Tags keywords.
Finally, notice that there is issue 174 about Pass keyword or other way to
stop execution prematurely with PASS status.