In the D&D 5e PHB, on page 211 there is a 1st level spell called Alarm. In the description, it has a sentence:
When you cast the spell, you can designate creatures that won't set off the alarm.
This leaves it a little vague as to whether or not said creatures must be explicitly stated, or whether general categories of creatures can be indicated. It makes sense to explicitly name party members, with the exception of the rogue, that will not set off the alarm. However, what about designating creatures by groups? Here are several examples:
- The city guards won't set off the alarm (some of which the spell caster knows and others they do not know)
- Tiny creatures won't set off the alarm
- Tiny insects won't set off the alarm (telling if something is tiny is not too bad, but how would the spell know if the creature is an insect)
- Good aligned creatures won't sent off the alarm
Are there any clarifications or restrictions on how one can designate which creatures the Alarm spell ignores?