The fourth volume of the handbook: "Best Management Practices to Deter Piracy off the Coast of Somalia and in the Arabian Sea Area" (known as BMP4) is the current authoritative guide for merchant ships on self-defense against pirates. The guide is issued and updated by "Oil Companies International Marine Forum" (OCIMF), a consortium of interested international shipping and trading organizations including the EU, NATO and the International Maritime Bureau. It is distributed primarily by the Maritime Security Centre – Horn of Africa (MSCHOA), the planning and coordination authority for EU naval forces (EUNAVFOR). BMP4 encourages vessels to register their voyages through the region with MSCHOA as this registration is a key component of the operation of the International Recommended Transit Corridor (IRTC, the navy-patrolled route through the Gulf of Aden). BMP4 contains a chapter entitled "Self-Protective Measures" which lays out a list of steps a merchant vessel can take on its own to make itself less of a target to pirates and make it better able to repel an attack if one occurs. This list includes rigging the deck of the ship with razor wire, rigging fire-hoses to spray sea-water over the side of the ship (to hinder boardings), having a distinctive pirate alarm, hardening the bridge against gunfire and creating a "citadel" where the crew can retreat in the event pirates get on board. Other unofficial self-defense measures that can be found on merchant vessels include the setting up of mannequins posing as armed guards or firing flares at the pirates.