Combat initiation types

[J-H]

To help me generate some encounter variety, I'm trying to put together some classifications.

Here's what I've come up with for "How an encounter starts":

Enemies surprised (party sneaks up on them, assassination during social encounter, etc.)
Party surprised (the reverse)
Mutual surprise / meeting engagement (typically two patrols meeting each other)
Deliberate movement to combat (both sides visible outside engagement distance, no surprise)
Enemy Defending fortification (pair with a surprise category)
Party defending fortification (pair with a surprise category)
Enemy pursuing party (chase)
Party pursuing enemy (chase)

Anything else?

[Tanarii]

Mexican standoff?

Also, since it's not technically the same thing: Iaijutsu / QuickDraw standoff
(According to TV Tropes this one is called Showdown At High Noon)

[Reversefigure4]

Multi-way combat (the party comes across orcs fighting wolves, both of whom will happily eat the PCs and each other)

Goal focused combat (not so much a combat -initiation- per se, but something like "both parties want to escape the burning building", "both parties want to retrieve the chest before it sinks too deep", which will radically change how the combat proceeds)

[Thrawn4]

Fighting retreat? You don't want to win, just to get out.

[Pauly]

Maguffin chase/scavenger hunt. Both parties want to retrieve and exit with the object.

Escort mission. One side is defending a person or persons. The other party wants to kill/capture the person. The person being defended may be stationary or need to exit to the next area.

Delay/distraction. One party wants to occupy the other party's attention and prevent them from moving elsewhere until a timer runs out.

Honor duel. Pre-arranged fight with preset win/loss conditions.

[Cactus]

Honour duel that is really a pretext to get close to the enemy army's camp which is right over the location of the portal the PCs need to jump through to return to their own time.

This really happened in a Pendragon campaign. We fought the duels first of course, because honour.