Relay acronyms

I couldn't easily find some of these relay acronyms, so here they are.

Switch

 * NO - Normally Open
 * NC - Nomally Closed
 * SPST Switch: A Single-Pole-Single-Throw
 * SPDT Switch: A single-pole-two-throw
 * DPDT Switch: A double-pole-double-throw
 * 2P2T (5 Port): This relay provides 5 ports that are in line. It differs from a DPDT by sharing one common output port with the two input ports. These relays are configured with ‘SMA’ connectors and can also be provided with internal terminations for the unused output ports. (Ports 1 and 5)
 * 4PDT - 4 Pole Double Throw
 * SP - Single pole
 * ST - Single throw
 * DP - Double pole
 * DT - Double throw
 * C - Common [contact]
 * MO - Manually operated
 * MC - Manually closed
 * SC - shown closed
 * SO - shown open
 * Form A - (normally open contacts)
 * Form B - (normally closed contacts)
 * Form C - SPDT
 * CO - ChangeOver

Contacts

 * AgSn - Silver-Tin
 * AgNi - Silver Nickel
 * AgCd - silver-cadmium
 * AgW - (silver-tungsten)
 * AgPd - (silver-palladium)
 * PGS -(platinum, gold, silver)
 * Au - gold

Transfer

 * MBB - make-before-break contacts
 * MB - make break
 * BBM - Break before Make

Power

 * A - amp
 * AC - Alternating Current
 * VAC - Voltage Alternating Current
 * R - [coil] Resistance
 * DC - Direct Current
 * VDC - Voltage Direct Current
 * HV - High Voltage
 * mA - milli-amp
 * W - watts (power)

Other

 * V.S.W.R. -Voltage Standing Wave Ratio
 * S - Set
 * R - Reset
 * SS - Solid State

Links

 * https://relcommtech.com/relay-terminology-guide/
 * https://www3.panasonic.biz/ac/e/control/relay/term/index.jsp
 * https://www.hascorelays.com/support/relays-terminology.html
 * https://www.digikey.com/en/blog/mechanical-relays-a-basic-overview
 * https://app.testguy.net/module/protective-relay-terms-and-definitions?r=263-Protective-Relaying-Terms-and-Definitions
 * https://oylair.com/wp-content/uploads/2021/03/resources-library-3-relay-terminology.pdf
 * https://www.relayspec.com/catalogs/002200/2005/002200_RFRelays_switches_Technical_Information.pdf