It is a habit present in the majority of MMO's to make the information readable in one glance.
In this case it means : path 3 of the dungeon, participating costs 2.5 gold
By the way this is against Arena.net politics, the gold is about paying for the dungeon run. 1-2 people that can solo/duo the run offer the last slots of the group at X gold to make profit.
In general in GW2 you can find those abbreviations too :
- AP, with for example : 5000AP min. This means 5000 Achievement Points are required to be accepted in the group
- AR, with for example 10+ AR. It stands for Agony Resistance, the statistic specific to fractals, and so 10+ means that you need at least 10 in this statistic to be accepted.
- Zerk for people requiring full Berserker gear
- 80s requires people to be at level 80 as some dungeons start being available before level 80
- Exp stands for Explorable mode, in opposition to story mode
- GC Gearcheck : people will make you link your gear to verify if it meets their requirements
And now in general in MMO's those are really frequent :
- LFG : Looking For Group (it can be LFP if you mean Party instead of Group)
- LFM : Looking For More (When a group is needing more people) (Credit to DavidYell)
- Exp : Experienced (you must know the instance/dungeon already)
(Credit to DavidYell for LFM meaning, to Amos M.Carpenter for 80s abd Exp in GW2 and to Daft for GC)
p3
would most likely meanpath 3
, but I'm not sure about the other one. Also don't necessarily expect logical or consistent abbreviations. From my experience in MMORPGs, people tend to develop lots of different abbreviations, especially in a game split between many different servers and sub-communities. As such I'd even say this might be off-topic here since you can't get a complete list. You may only try to list the most popular abbreviations, but even those are subject to change depending on which server you are, which time zone, region, etc.