Override givens are optional.
@@ -215,7 +215,7 @@ variables in a population.
the baseline generative model *baseline*. The *customization* is a
comma-separated list of clauses customizing the metamodel:
- ``OVERRIDE GENERATIVE MODEL FOR <target> GIVEN <variable(s)> USING <predictor>``
+ ``OVERRIDE GENERATIVE MODEL FOR <target> [GIVEN <variable(s)>] USING <predictor>``
Specify that the variable *target* is to be predicted by
*predictor*, conditional on the input variables
