Jack in

The action of Jacking-in is when a net operator sends his or her NetNavi from the PET into the cyber world. In the first three Mega Man Battle Network games, the PET used a wire that plugged into the jack of an electrical unit. From Mega Man Battle Network 4 on, all Navis jacked in wirelessly. To jack-in with MegaMan.EXE in the games, Lan Hikari would have to be standing considerable close to the jack-in port. The act of "Jacking-out" is the opposite operation.

When a Navi is in the cyber world, the operator can disconnect without jacking them out but they cannot send Battle Chips to their Navi without a connection. Also, if a Navi loses its connection with its operator, the Navi can only jack-out by manually returning to the original jack-in site.

In Mega Man Battle Network 2, Lan receives a wireless port adapter before leaving to Netopia. Lan uses this twice. Once when a port is out of reach due to a trap and the other that was too far to reach without going near Princess Pride. The wireless adapter allows MegaMan to jack-in through the "wireless field". The wireless is essentially the predecessor to the wireless PET's introduced in Mega Man Battle Network 4 on.

In the Japanese version of both the game and anime, the phrase is "Plug-in". Netto (Lan) is the only one who includes ".EXE" whenever he plugs in.

Notable Quotes
Most net operators call a sort of battle cry before jacking-in their NetNavi by yelling out their Navi's name.
 * Lan Hikari: "Jack-in! MegaMan.EXE transmit" (Mega Man Battle Network)
 * Lan Hikari: "Jack In! ProtoMan, Execute!!!" (Mega Man Battle Network 5)