0953 ( ॓ ) DEVANAGARI GRAVE ACCENT
0954 ( ॔ ) DEVANAGARI ACUTE ACCENT
I saw this earlier but just remembered when i saw pango renders U+0953 and U+0954 characters as independent vowel even though they are dependant(dont know what is exact problem).
Unicode Public Review issue 122 dated 2008-08-04, has proposed these two characters as deprecated.
As a devanagari script user i have never used these in my writing, but i think these two characters are added specifically for vedic.