Like how long EXACTLY? That's all this rule needs to be seriously taken as the rule.
It apparently depends on the situation, if you have two groups (or just two ships that is) that are about to enter in a clash with each other, having a line of short RP and then engaging could be understandable aka LN vs RM or Order vs Core situations.
However, decloaking on someone and unleashing hell on them two seconds after a mere one line of RP was dropped is something sanctionable I think.