Named Block Conventions

• The name of a named block is case sensitive; for example, ABC is not the same as aBc.
  
  
• The named block name is left-justified and padded with nulls to eight bytes. All eight bytes are used and compared regardless of content.
  
  
• All annotation marks allow any number of named blocks to be associated with them. Each named block is associated with one and only one structure. A mark cannot have multiple blocks with the same name.
  
  
• All names beginning with Oi (Oixxxxxx) are reserved.