"Sixteen Rules" issue
The core of Esperanto propaganda has long been the claim that it has only 16 rules (dekses reguloj) of grammar.
Properly put, the baseline of Esperanto (the Fundamento) has 16 rules, stated very elliptically, and intended for people already familiar with European grammars. Good standard Classical Esperanto, as used by Zamenhof and his contemporaries, emulated by the modern cultural elite, and codified in the Plena Analiza Gramatiko, obviously has a good deal more than 16 rules of grammar.
Outside the elite, the "16 rules" recur in Esperanto propaganda, and instigated piece of counter-polemic, written by Athelstan, in which Lojban was described as having only "10 rules". The point of the exercise was that the "16 rules" are nonsensical as a be-all and end-all of Esperanto grammar, and cannot be used to lord it over Lojban. The counterpolemic instigated counter-counterpolemics, and so forth.