Today I collected house numbers in the Phase 4 development of Taze Zaman, a planned community in the northwest quadrant of Ashgabat. To my surprise, street signs in the new phase in a couple of cases show alternate spellings for the names of the streets. In the old phase, Ebedilik and Abadanlyk are the names of the streets; in the new phase, they are spelled Ebediýlyk and Abadançylyk. Since OSM recommends naming streets as their signs read, the streets are split between the alternate spellings.
At any rate, all houses are now numbered, using the addr:interpolation tag on lines drawn between address points at the end of each city block. The houses are cookie-cutter, so the interpolations should be pretty accurate.