diff --git a/openff/toolkit/typing/engines/smirnoff/parameters.py b/openff/toolkit/typing/engines/smirnoff/parameters.py index ac4236858..c3ff461c1 100644 --- a/openff/toolkit/typing/engines/smirnoff/parameters.py +++ b/openff/toolkit/typing/engines/smirnoff/parameters.py @@ -2063,11 +2063,15 @@ def add_parameter( The SMIRKS pattern (if str) or index (if int) of the parameter directly after where the new parameter will be added - Note that one of (parameter_kwargs, parameter) must be specified - Note that when `before` and `after` are both None, the new parameter will be appended - to the END of the parameter list. - Note that when `before` and `after` are both specified, the new parameter - will be added immediately after the parameter matching the `after` pattern or index. + Note the following behavior: + * Either `parameter_kwargs` or `parameter` must be specified. + * When `before` and `after` are both `None`, the new parameter will be appended + to the **END** of the parameter list. + * When `before` and `after` are both specified, the new parameter will be added immediately + after the parameter matching the `after` pattern or index. + * The order of parameters in a parameter list can have significant impacts on parameter assignment. For details, + see the [SMIRNOFF](https://open-forcefield-toolkit.readthedocs.io/en/latest/smirnoff.html#smirnoff-parameter-specification-is-hierarchical) + specification. Examples --------