Three separate traditions divide the Moon's monthly path against the stars, and because all three are called lunar mansions in English they are persistently confused. They are not variants of a single scheme, and this atlas records all three separately.
The Indian nakshatras number twenty-seven, each of thirteen degrees twenty minutes, measured along the ecliptic in the sidereal frame. They are attested in the Vedic literature well before any contact with Greek astronomy, they carry presiding deities and symbols, and they are the backbone of the Vimshottari dasha system. A twenty-eighth, Abhijit, appears in some sources, inserted near the end of Uttara Ashadha; it is used in certain muhurta calculations and omitted from the standard twenty-seven-fold division, which is why the count is sometimes given as twenty-eight.
The Arabic manazil al-qamar number twenty-eight, each of twelve degrees fifty-one minutes. They descend from the pre-Islamic anwa, a system of stellar risings and settings tied to weather and the agricultural year, and they were later given magical significations that passed into Latin Europe through the Picatrix and from there into the grimoire tradition. Their names are Arabic star names, and this atlas records them under those names.
The Chinese xiu, sometimes called lodges, number twenty-eight and are of markedly unequal width. They differ from both other systems in a fundamental way: they are equatorial, marked by determinative stars and measured in right ascension, not ecliptic divisions at all. They are grouped into four palaces under the Azure Dragon, Vermilion Bird, White Tiger and Black Tortoise.
Whether the three systems share an origin is a genuine open question in the history of astronomy, and has been argued for over a century without resolution. The equatorial character of the Chinese lodges is the strongest evidence for independent development; the shared count of twenty-eight is the strongest evidence against it. No consensus exists.
What can be said without dispute is that they are not interchangeable. A nakshatra is not a manzil, and neither is a xiu.