For things that we can't put on the site, because we don't know what they are.
What: A Manhole that says "F.S.P.B.W."
Where: ??
Discussion: https://twitter.com/netsofphilly/status/1025821948893388802
Explanation: Might have something to do with the Philadelphia, Baltimore, Washington Railroad (PB&W). Probably actually has something to do with water. Check out these images of other water-related manholes with the same checkerboard pattern [1][2].
What: A green pedestal with no markings.
Where: 22nd and Market.
Discussion: https://twitter.com/netsofphilly/status/1029371419413676032
Explanation: Not sure, might be related to the Electrical Bureau or SEPTA based on location, though green is sometimes a color for traffic signals. More pictures [1][2][3].
What: Several antennas and boxes on a light pole.
Where: 19th and Ludlow.
Discussion: https://twitter.com/netsofphilly/status/1035163216991723520
Explanation: This is definitely a small cell!