I don't know if that's kosher, either, but perhaps it counts as promotional work for the Star Charts
There were some maps visible onscreen in DS9, on which that linked map is based, but while those maps gave the location of Bajor, Cardassia and Ferenginar, plus some idea of distances, they never gave the location of Earth.
It's just guesswork that Earth would lie in the middle of the "hollow" suggested by those onscreen maps, a hollow of neutral space against Cardassian space, with its border at Bajor. The idea behind the interpretation is that Earth fought a war against Cardassia in the recent past, getting as far as Bajor, and then stopping because the fight would have gotten too bloody from that point on. But instead of conquering the former Cardassian territories and allies, it withdrew at the end of the war and left the space neutral.
The scale of the onscreen maps, plus a suggestion in the DS9 Technical Manual made by the same people who made the onscreen maps, resulted in Earth being about 50 lightyears away from Bajor in that linked Star Charts
map. 50 ly is a rather plausible distance for a starship to cover in a week or so, like our heroes generally did in DS9 ("The Search", "Paradise Lost", "Defiant"). Not very far, but certainly at the frontier, because one can't get any farther in that direction... Not without a warfleet, at any rate.