737NG Flare Retard
 

In the 737NG Boeing Maintenance Manual, it states that if the DFCS is not engaged for the approach, the A/T goes into flare retard at 27ft radio altitude if on Glideslope in MCP Speed Mode and flaps more than 12.5 degrees.

I'm hoping someone has a technical definition of "on Glideslope" in this situation? Do I still need FD's on, APP mode selected, valid frequencies selected, valid glideslope signals, correct course dialled in, beam deviation within certain limits, etc?

Thanks.
Regards.
Q.