Quote Originally Posted by Deceptus View Post
[External] Mitigation
Buffs
Debuffing enemies
Healing
Damage
Rez

All of the above encapsulates the Support Role.
If this were to actually come down to a matter of categories, rather than playflow, shouldn't we note that not even one of those is unique to Healers/"Supports", though?
Tanks have external and internal mitigation. Melee DPS have internal mitigation.

Most DPS have external buffs.

All debuff enemies.

Most can technically heal.

All can damage.

Most Magical DPS also have rez.
And, heck, Chain Strategem is merely a worse (in being limited to a single enemy target) raid buff.