Thank you both ColC and Forfarian, but having also had dialogue with ScotlandsPeople it turns that CH2 is "Church of Scotland kirk sessions, presbyteries, synods and other bodies (NRS reference CH2), 1569-2006"
This entry: RUSSELL HELEN JOHN RUSSELL/CATHERINE HENDERSON FRCH2V26 FOUND IN 1827 U 11/11/1818 479/260 19 Falkirk
was found in: "Kirk sessions records, births and baptisms, 1784-1860, marriages 1783-1784, proclamations of marriage, 1855-1860, Falkirk GS film 304668".
It seems that CH2 record can be found on FamilySearch as "Kirk session minutes, CH2/400/13, November 1803-January 1833 GS Film 4101322" but it is hasn't been indexed yet.
Thank you for all your help.
Shirlee
from a very wet Wellington, NZ