Authors CurseForge

Back in February Elsia documented the following;

SPELL_DAMAGE has 11 optional arguments.
optarg1 = unclear, a number
optarg2 = spell name
optarg3 = unclear, a number (e.g. 4) (4 for fire damage (e.g. immolate), 32 for shadow damage (e.g. shadow bolt)
optarg4 = damage amount
optarg5 = unclear, a number (e.g. 4) (seems to match optarg3)
optarg6-11 = nil

This morning I've discovered this;
optarg9 = Spell/Skill crit flag (not nil if spell/skill is a crit)

For SWING_DAMAGE the same flag is optarg6 as documented.
I couldn't find anywhere that this has been written, hope it helps.