White paint on rear lamp cluster

[GSD]

I think my car tail light has been hit by a white vehicle. There is a white "paint" mark about the size of a fingernail on the cluster which is acrylic. Applying brasso to the paint has not dissolved it or removed it and it is resisting gentle abrasion and scraping. Its more an irritation than a serious problem but does anybody have any suggestions how to remove.
Oh and before you ask it's definitely no bird poo !

 

[GSD]

Prompted by the thread below I tried WD 40 which softened paint enough to scrape off with fingernail.
Job done!!