Bits 0-3 are used by the classroom-based command lists to indicate that or check whether a teacher has arrived at the classroom door to start the lesson.

Bit(s)	Meaning if set
0	Teacher has arrived at the Map Room
1	Teacher has arrived at the Reading Room
2	Teacher has arrived at the Exam Room
3	Teacher has arrived at the White Room
4-6	Unused
7	EINSTEIN is speaking (set by 7CAF; checked by 79BA and 7CC8; reset by 79CA)