Definitions containing the term calling drop

What does calling drop mean?

800	Toll-Free Calling Regional » US Phone Area Codes
CLID	Calling Line IDentification Computing » Networking
OADM	Optical Add-Drop Multiplexer Academic & Science » Electronics
DEAR	Drop Everything And Read Community » Educational
877	Toll-Free Calling Regional » US Phone Area Codes
888	Toll-Free Calling Regional » US Phone Area Codes
LDO	Low Drop Out Community » Educational
LDO	Low Drop Out Academic & Science » Electronics
DNH	Drop N Harmony Community » Performing Arts
DSDM	Drop Site Database Manager Computing » Databases
3WC	Three Way Calling Computing » Telecom
PVDS	Plant-Verified Drop Shipment Miscellaneous » USPS
D/I	Drop and Insert Computing » Telecom
SLDI	Sector List Drop Interval Governmental » Transportation
WYDI	Westhoughton Youth Drop In Community
ODZ	One Drop Zendo Miscellaneous » Unclassified
DIMS	Drop In Manifold System Miscellaneous » Unclassified
ACAU	Automatic Calling/Answering Unit Governmental » Military
DZAAS	Drop Zone Assembly Aids System Governmental » Military
WQCL	Western Quail Calling Lesson Community » Sports
ODZA	One Drop Zendo Association Business » Professional Organizations
ADM 3X	DS3 Add-Drop Multiplex Computing » Telecom
YYDC	Ypsilanti Youth Drop-in Center Community » Non-Profit Organizations
QRZ	Who is calling me? Academic & Science » Amateur Radio
WADM	Wavelength Add/Drop Multiplexer Academic & Science » Electronics

Calling Drop: In a telephone exchange or telegraph office a drop shutter annunciator, which falls to call the attention of the operator, notifying him that the line connected to such drop is to be connected to some other circuit.