Note:The "specification" usually refers to the whole document including the claims

Cover Page

• Prepared by patent office except for abstract, which inventor prepares

Disclosure/Description

•  Clear and concise written description of the invention and its usefulness, including drawings
• Must be so clear and complete that it will enable anyone with average skill in the technology to make or use the invention
• Contents: 
  •  Title of the invention  
  • Statement of patent history  
  • Field of the invention 
  • Background  
  • Summary of the invention in broad terms 
  • Drawings  
  • Brief description of the drawings  
  • Detailed description of the invention

Claims

• Define boundaries of patent protection
• Written statement of what the inventor asserts is his or her exclusive property
• Information specified as protected by the claims cannot be used freely (copied, manufactured or sold) by others until the patent expires
• Information not protected by the claims can be used immediately by anyone

Beside each item on a patent cover sheet there is a number inside a square bracket. These numbers, the INID codes, are international standards that identify the type of element in a patent document for most countries in the world. Below are a select list of categories, for the complete list of the codes refer to  Appendix 1 in WIPO Standard ST.9.

[11] Patent Number

[12] Document Type

[21] Application Number

[22] Date of Patent Filing

[45] Date of Patent Publication/Issue

[51] International Patent Classification

[52] Domestic or National Classification

[54] Invention Title

[57] Abstract or Claim

[56] List of Prior Art Documents (aka References Cited)