The second letter is probably the initial of the moneyer who made these coins, while the meaning of the first letter Ha (which appears on almost all types of these "4-dot" coins) is unknown. These coins were previously attributed to pre-Islamic Sindh, but they are not re-attributed to the Northern Punjab and the surrounding area, and were probably minted in the domain of the early Hindu Shahi since the areas where these coins are found was directly controlled by the Shahi dynasty at the relevant time. These coins were probably made obsolete when the Shahi moved their capital was moved to Kabul and began striking the famous horseman/ bull silver drachms which became ubiquitous in northern India.
Four dots and various lines, probably representing the extreme degeneration of a bust or a horse, Brahmi letters "Ha" and "Gu" / Blank. 15mm, 1.23 grams. Fishman/Todd "The Silver Damma" #GA6; JONS 201, Fishman type 9A.