These are the rules for vowel diacritics in Ranjana script. There are altogether three rules where the vowel diacritics of क, ग and ब are given.
ख, ञ,ठ,ण,थ,ध,श uses the rule of ग
घ,ङ,च,छ,झ,ट,ड,ढ,त,द,न,न्ह,प,फ,ब,भ,म,य,र,ह्र,ल,ल्ह,व,व्ह,ष,स,ह,त्रuses the rule of ब
ज,म्ह,ह्य,क्ष ,ज्ञuses the rule of क