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 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)