Layout of a Business Letter — SPCC STD 11 Commerce — Question

Parts of layout of Business Letter : Various parts of business letters generally are as follows: Keeping writing of business letter as base the letter can be divided into two parts (A) Regular parts of letter (B) Occasional parts of the letter. The regular parts of the letter can be found same in all the business letters. Their placement is fixed, so it could be found at same place in all the business letters. Occasionsal parts of the letter are used as per the need. The details of both the parts are as under.
[A] Regular Parts of a Letter:
(1) Heading(2) Date(3) Inside address (4) Salutation (5) Body of the letter (6) Complimentary Close (7) Signature
[B] Occassional Parts of a Letter:
(1) Personal Notation(2) Attention Line(3) Subject Line (4) Encloser(5) Carbon Copy Notation (6) Identification Line (7) Mailing Instructions (8) Postscript