Clearly understood words should be coded. Sounds that refer to entities, properties, and events, in addition to onomatopoetic and conventionalized evaluative sounds are able to count as words in young populations.

Gestures should be symbolic communicative hand motions that are not directly manipulating an object. Exceptions can be made for show gestures, where a child carries an object over to a caregiver to show what it is. Show gestures can be coded as deictic gestures, similar to pointing gestures. It might be necessary to have a unique gesture vocabulary created for coders that are specific to each individual being evaluated.