Clue: Poster about one Glaswegian golf club perhaps (7,4)
Answer: PLAYING CARD
Explanation: Definition: club perhaps

**PLACARD** ("poster") *about* **YIN** ("one" to a "Glaswegian") + **G** (golf)
 

 
*Billy Connolly, the famous Glaswegian comic, is also known as the Big Yin.