Glancing down near the intersection of 18th and Locust Streets near Rittenhouse Square, Carolyn Rogers can’t help but do a double-take.

“The space between this sign and the building is not dedicated to the public,” proclaims the brassy plaque inlaid in the sidewalk.

“I’m always like, ‘Am I reading this right?’” Rogers said. “Not dedicated? Should I not walk there?”

Rogers asked about the signs scattered around the city’s pavement through Curious Philly, a portal that allows readers to ask Inquirer and Daily News journalists their questions about the Philadelphia region.

"Space within building lines not dedicated" sign at the Philadelphia Federal Detention Center.
Oona Goodin-Smith / Staff
"Space within building lines not dedicated" sign at the Philadelphia Federal Detention Center.

Some of the metal inlays say “the space ... is not dedicated” while others proclaim “property behind this plaque not dedicated,” but in the end, they’re saying the same thing.

“Dedicated to the public,” in this case, is a legal phrase, defined by Black’s Law Dictionary as “an appropriation of land to some public use made by the owner, and accepted for such use by or no behalf of the public.”

The signage occurs when a building’s property line extends past the dimensions of the structure. In other words, the property owner owns more land than just the building.

So, “not dedicated to the public” means that the space of sidewalk between where that metal sign stops and the building begins technically isn’t public property.

Although the plaques are placed to protect the property owner’s rights, you’re welcome to walk in the “not dedicated” space, but technically, it’s private property, University of Pennsylvania Architect Charlie Newman said in a feature on the school’s website.

The plaques can be found throughout the city, from Penn’s campus in University City to the Federal Detention Center on Seventh and Arch.

A "property behind this plaque not dedicated" sign on Arch St. near the Federal Reserve.
Oona Goodin-Smith
A "property behind this plaque not dedicated" sign on Arch St. near the Federal Reserve.

It’s a safeguard in place to protect against a real estate legal loophole known as “prescriptive easements,” PlanPhilly’s Jim Saska wrote in a 2016 column about the curious corner pieces.

“Prescriptive easements” are another bit of legalese, meaning those who use an area for 21 years or more are extended rights to the land, as explained in the Pennsylvania Law Monitor.

So, in other words, if Philadelphians were to traipse down Arch Street on the 12 inches of pavement between the technical property line of the Federal Reserve and the building’s wall for 21 years straight with no “dedicated” plaque in sight, the property would become the public’s, too.

That’s where the plaques come in. With a little legal language bolted to the ground, the property owner is letting you know that you can walk there, but you don’t own it.