Sentence:  Available , <WSD>on</WSD> request , from U.S. Department of Agriculture , Washington 25 , D.C. , are : Cooperative Farm Credit Can Assist in Rural Development ( Circular No. 44 ) , and The Cooperative Farm Credit System ( Circular No. 36 - A ) . 
Meaning of the word marked with <WSD> tags:  on the occasion of a request