cue sheets  

Sheets which indicate contents of mix for use by the mixer(s).  Usually read up to down (time) and left to right (individual tracks).  There are specific graphic conventions to convey information such as fade in, fade out,  track contents, etc..
Cue sheets take a variety of forms.  Different studios may prefer different styles.  Some of the digital editing systems will generate cue sheets automatically.  With the use of Digital Audio Workstations in the mix, the mixers may not need a cue sheet.  Despite this, the sound designer and other sound crew present should have one at the mix, if only to remind them of what is on which track at any given moment.