STR 15 3d6 [1] means...?

[Dr Rotwang!]

Though no stranger to HERO rules, I keep seeing numbers in brackets following damage codes and I don't know what they mean.

Thanks for your help in advance!

[Steve Long]

It means the STR does 3d6 damage, and costs 1 END to use.

When used in the "END" column of a character sheet, a number in brackets indicates Charges; END costs are listed as normal numbers.