Why is this an issue?
NOT prefix operator twice does nothing: the second invocation undoes the first. Such
mistakes are typically caused by accidentally double-tapping the key in question without noticing.
Either this is a bug, if the operator was actually meant to be called once, or misleading if done on purpose.
Noncompliant code example
IF NOT ( NOT foo = 5 ) THEN -- Noncompliant
value := ++1; -- Noncompliant
IF foo = 5 THEN -- Compliant
value := +1; -- Compliant