Green’s Dictionary of Slang

Janet Street-Porter n.

[rhy. sl.; ult. UK journalist and broadcaster Janet Street-Porter (b.1944)]

(drugs) a quarter ounce of cannabis.

[UK]Guardian 28 Jan. 22: A rhyming slang web site reports that people seeking just over seven grams of cannabis now routinely say to dealers: ‘Oi, guv’nor, gissa Janet Street-Porter.’.