Letter of credit

The allowable period of time, permitted by custom, between the date of bill and its payment. The usance of a bill varies between countries, often ranging from two weeks to two months. 2. The interest charged on borrowed funds. Usance is derived from the action of usury.

ANUJ SAXENA

you can get full knowledge from google search engine regarding LC .To get Deep Knowledge you should know about UCP (Uniform Custom Practices) also  for accounting part just learn what it is .to know in depth you should acquire expert knowledge