TR — Technical Regulation or Technical Reglament (the same meaning applicable in CU documents)
LVE — Low Voltage Equipment LVD — Low Voltage Directive applicable for LVE EMC — Elrctro-Magnetic Compatibility applicable for LVE MD — means Machine Directive. For example, all electrical tools (like electric drill, planer etc) falls under 3 technical regulations: LVE + EMC + MD.
CU — Custom Union of 3 countries (it was until 2016): Russia, Belarus and Kazakhstan. Now it's reorganized into EAEU. EAEU — EurAsian Economic Union of 5 countries: Russia, Belarus, Kazakhstan and joined them Armenia and Kirghistan. So CU and EAEU is territory only.
CU TR or EAEU TR — Technical regulation of CU or EAEU are the same. So CU TR are equal to EAEU TR. If an equipment meets all requirement of all TRs applicable to the equipment in this case it should be marked by EAC mark.
EAC mark — EurAsian Conformity mark.
GOST mark — Russian national certification mark.
CoC — Certificate of Conformity DoC — Declaration of Conformity The procedure how to approve the equipment — by certification or declaration scheme — CoC or DoC is specified by specific CU | EAEU TR applicable.
FAC — Federal Agency of Communication — a part of Russian Digital Ministry (under reorganization now)
PTN — Public Telecom Network is civil wire, optic, radio network for commercial services
GKRCH — federal multi-sectoral commission for frequency distribution
RFC — regional (local) Radio Frequency Center for monitoring of frequency usage