List of known procedure types:

Attack & Restore

The most classical duality there is. Naturally a system you try to invade simply tries to disconnect you. But just as well you can disconnect their security bots or even an other human.
In 'defense' there is reconnect software. As one would expect the winner in a direct conflict disconnect-reconnect is clearly the disconnector. It is something you learn early. You have to be active to achieve your goal. Reconnecting can only be a delay tactic in the long run.
Something to remember is that an attack does not directly disconnect a library. The software is too sophisticated for that. Instead, a feedback loop is built up in the deck. Given enough buildup this feedback rips everything apart that is connected to the deck - library or human brain. At that point a hacker should know it is time to leave immediately

Intrude & Guard

Alternatively to the rather brute disconnection attempts, one can also go a second way. Quickly intrude the core of the operating system. Then kick on its disconnection procedures. If done successfully the enemy is immediately disconnected from the system. Most libraries do automatically try this attack, but the hacker can aid them with intrude procedures, or hinder the enemy with guard ones. Note that you cannot repel an already made success. So the longer a hack lasts, the higher the chance to fall victim to a successful intrusion.

Crashing

This is probably the most mean type of attack. It is not geared at disconnection someone from the system; not even aimed at the library itself. Instead a crashing attack is aimed directly at the hardware involved. Such attacks will directly damage the enemies' deck if successful.
Fortunately crashing attempts they are easy to avoid as long as one knows the over all system state well enough. Only linked with large scale disturbance attacks a crashing attempt might work. But then it hits brute and fast, not needing the buildup time of Attack or Intrusion.

Target & Evade

These two are only applicable against other hackers or defense bots. As a part of their design all libraries got a certain stealth ratio. Target and evade procedures are aimed at changing these natural stealthiness. A target procedure might do the same as placing a streetlight next to him, while Evade employs camouflage skills.
Again it is easier to reveal something as to hide oneself.

Shield & Soften

The shield procedures of a library are the last line of defense against an attack. This fact however also makes the shielding of a lib a top priority target. A soften procedure does exactly this. It weakens the shielding to bring a later attack to full effect. In defense one can create additional resistance with a shield procedure. In the long run one should rather attack the enemy then to try and hide behind shields of course.

Protect & Unprotect

Protection mainly concerns the self encryption rating of a library. The better something is protected, the harder to influence that thing. However that also means that the owner of the library cannot reconnect that easily for example. So unlike target, an unprotect executed at oneself actually might be a good idea.

Transmit & Disturb

Transmissions are the natural connection of a library to its user. With a transmission command a user can request additional updates of the current system state, thus often providing a higher rate of success for later procedures. The adversaries of transmissions are disturbing signals. Sent at the right time, they can block practically every action of the victim.
One should note however that unlike all prior examples here the constructive Transmit will win over the destructive Disturb. If only because everything automatically transmits slowly even if not prompted to.

Firewall

Another very nasty type of procedure. It does not do anything of its own, instead it is an activity creator. Every run procedure instabilizes a system a bit, as it tries to get rid of the foreign software. A firewall type procedure encourages that behavior up to insane values. It generates procedure like activity until the system reacts and builds up defenses against that intruders. So the name Firewall is a bit misleading as the procedure itself does not implement such a thing. It just triggers defenses - practically rendering certain procedures unable to run for a certain amount of time.

Virus

Another very interesting type of attack. Just as a Firewall it also attempts to modify the target system. However it goes even further then a Firewall. A virus actually changes general system stability. A dedicated virus might for example be able to close a couple of backdoors in the graphic subsystem, thus making it harder for an attack to happen there. Another one might open some new exploits in the network layer making disconnects so much easier.