Currency is related to Note. Note is a synonym of Notice. Notice is related to Post. 
you are likely to find Assignment in/at/on Desk. you are likely to find Notebook in/at/on Desk. you are likely to find Paper in/at/on Notebook. 
Currency <--RelatedTo--> Note <--Synonym--> Notice <--RelatedTo--> Post 
Assignment --AtLocation--> Desk <--AtLocation-- Notebook <--AtLocation-- Paper 