Also the Additional Act /A/SA.1/12/16 Relating to the Enhancement of the Powers of the ECOWAS Parliament at its Article 20, in line with the ECOWAS General Convention on Privileges and Immunities of 1978, reproduces in the same vein the content of Article 9 of the Protocol on Parliament (cited above), reiterating parliamentary immunity and stating that any request for waiving of a Member's immunity shall be addressed to the President of Parliament (Article 21). Within the framework of parliamentary immunities, there is a difference between irresponsibility or material immunity and inviolability (also referred to as substantial criminal immunities and procedural criminal immunities or immunity in the strict sense). The parliamentary irresponsibility (or material immunity) means that Parliament Members do not incur civil and disciplinary liability because of the votes and opinions they cast in the performance of their duties. It is absolute, perpetual and permanent, and Parliament Members are free from civil, criminal and administrative actions which, pursuant to the opinion votes expressed in the performance of their duties, may be directed against them. The inviolability (or procedural or immunity in the strict sense) shall mean that Parliament Members shall not be subjected to detention, imprisonment, mere hearing (as deponent or defendant) or trial for any other acts, save as otherwise provided in the Constitution or the Law and with the formalities provided for therein. That is, this immunity does not to exempt the Parliament Member from being detained, arrested, heard or tried, but it only prohibits it without the authorization of the Assembly, which will then be able to check whether there is any indication that justify maintaining these immunities. Unlike the parliamentary irresponsibility, the immunity in the strict sense has a limited, provisional and temporary character and is valid only in criminal proceedings and extends only for the duration of the mandate. 12