If a command has "When I say" disabled, creating a command that uses dynamic command sections to generate that same phrase will result in it not getting recognized.
E.G.
If a command with a "When I say" value of "test command" exists, but is voice disabled, creating a command with a "When I say" value of "[test;] command", which is accepted(an exact duplicate is not), speaking "test command" writes "Unrecognized : 'test command' to the log and not executing, while speaking "command" results in the (latter)command executing.
EDIT: Fixed; Tested with v1.8.3.21