Typographic Conventions

To help you understand the material in this Data Handbook, we will use a few consistent typographic conventions.

Visual Cues

The following typographic cues are used:

  • bold words identify a Python library or function
  • typewriter-like words identify a file name, system command, or response that is typed or displayed.
  • italic type indicates a new term, an important point, a mathematical ­variable, or a task parameter.
       identifies a header keyword.
  • ALL CAPS identifies a table column.


Occasional side comments point out three types of information, each identified by an icon in the left margin.

Warning: You could corrupt data, produce incorrect results, or create some other kind of severe problem.

Heads Up: Here is something that is often done incorrectly or that is not ­obvious.

Tip: No problems... just another way to do something or a suggestion that might make your life easier.

Information especially likely to be updated on the COS Web site is indicated by this symbol.