It's all right there for you, with an example.
# This will allow a player to buff himself and others around him
# for a certain amount of time, this also works on groups
#
# Note that only 1 buff is allowed at the same time.
#
# Amount = 1
#
# 1.BuffSpell = 1
# 1.BuffSTR = 20
# 1.BuffINT = 20
# 1.EXPRate = 120%
# 1.DropRate = 120%
Spell 1 will buff your groups str and int by 20 each, and exp rate/drop rate by 120%.
I just tried it on my server, so small heal would buff my group. I didn't edit my pubs at all, just ended 1(amt id)BuffSpell = spellID.