As the rules say, people are NOT allowed to kill people who have just spawned and are resting in the spawn-zones.
Thing is though, it's difficult to discern who's lying and who's not, so we require screenshots that actually show you were resting after spawning and someone killed you when you were on low health.
The rule for spawn-killing does not apply if someone runs into a spawn point though after getting hit. This is not a game of hide and seek, or chase. You can't just run to the spawn point and say "this is a safe zone", because you were neither afk then, nor regenerating after a spawn.
If you don't want to be involved in PK'ing you just don't go in PVP maps. Pvp maps are called that because they are that - open pvp maps.