(m)

The RuneScape Wiki also has an article on: rsw:(m)

(m) is a suffix used to denote an ale as mature, which simply means having a stronger effect than their non-mature counterparts. Ales contained in calquat kegs may also have the mature suffix, paired with a numerical value relating to the number of servings remaining. Glasses of mature cider and mature wizard mind bombs do not have this suffix, but the kegs do.

Ales

• Asgarnian ale(m) and keg variant
• Axeman's folly(m) and keg variant
• Chef's delight(m) and keg variant
• Dragon bitter(m) and keg variant
• Dwarven stout(m) and keg variant
• Greenman's ale(m) and keg variant
• Moonlight mead(m) and keg variant
• Slayer's respite(m) and keg variant
• Cider(m) (keg)
• Mind bomb(m) (keg)