In 2010, I began documenting the symbols which I first found in the stairwell of the Yangtze Cinema, a small cinema in the now-demolished Pearl Centre that largely showed R-rated films. Similar symbols were found in the Rochor area.
The symbols are quite particular - they all have numbers and a drawing of a couple and are encircled by a phallic symbol.
In Singapore where graffiti is illegal and street furniture is routinely cleaned, there is very little authentic street art. These faint marker symbols are much more intriguing to me than any other graffiti found on the streets of Singapore.
Documentation on my blog over the years:
Mar 2012 - Yangtze Scribbler on Victoria Lane
April 2012 - Looking for the Yangtze Scribbler
June 2012 - Yangtze Scribbler on Queen Street
May 2013 - Yangtze Scribbler on Victoria Street
March 2016 - Yangtze Strangers