An interesting thread played out on the Originally from Dorchester Facebook page over the last week after someone posted a map of Boston’s neighborhoods that included a sub-division of Dorchester into two sections, “north” and “south.”

The feedback was immediate from many of the page members— now more than 12,000 strong— who were mostly puzzled by the division.

“When did all this north and south Dorchester start” Mary McDavitt wanted to know. “North and South Dot??? Bogus map! There is only ONE Dot!” chimed in Tom Fitzgerald. “I’ve never heard that before!” said Kathy Taylor-Roy. “There is only one Dot!”

Peter Connolly counseled his fellow members— accurately— that the terminology has its genesis in the days of “urban renewal”— the same period that saw the destruction of the city’s West End.

“There is no ‘South Dorchester’ or ‘North Dorchester,’ just Dorchester,” wrote Connolly. “‘North Dorchester’ was dreamed up by bankers & loan officers to codify a certain section of Dorchester as black. It’s divisive.”

Most members of the OFD page— which is moderated in part by the Reporter’s editors— live outside the neighborhood, with some hailing from across the world. The page has become a popular stop for many in the Dorchester diaspora — a way to share memories and re-connect with childhood friends.

It’s telling that the consensus on the OFD site is that the “north-south” division has no real roots among the people who’ve called this place home over past generations. It’s been our policy— since our launch in 1983— to refuse to print it.

Our beef is three-fold: First, as Peter Connolly suggests, this is an artificial line created during the Jim Crow era to divide Dorchester along racial lines. It was a form of redlining, pure and simple, an insidious vestige of segregation.

Secondly, it makes no sense geographically. Past city administrations that used it more heavily assigned Savin Hill to “south” and Codman Square to “north.” Absurd.

Thirdly, the terms are not authentic, meaning: Dorchester people themselves do not use them. As the OFD thread underlines, the terminology is foreign to the ears of people who grew up here in the mid-20th century.

In 2013, during the last mayoral election, the Reporter made the continued division of Dorchester a campaign issue. We asked the field of candidates to pledge to do away with the North-South divide within City Hall. Marty Walsh was one of those who agreed that it was time to do just that, asserting, “Those designations of North and South Dorchester should absolutely be done away with. No question.”

We have seen progress on this front under Walsh’s watch. His signature planning initiatives have consistently used just Dorchester. The BPDA, the successor agency to the one that promulgated this affront, the old BRA, has stopped using the terms.

But there remains more work to be done. The city’s Boston Public Health Commission continues to divide Dorchester in its reports and publications. The mayor should crack down harder and issue an order to all city agencies to eliminate the usage in future communications.

Edward Podolski, one of the commenters on the OFD page, summed it up nicely when he wrote, ”Dorchester PERIOD.”

Amen.