The .info file is a static text file for configuring a theme. Each line in the .info file is a key-value pair with the key on the left and the value on the right, with an "equals sign" between them (e.g.
name = my_theme). Semicolons are used to comment out a line. Some keys use a special syntax with square brackets for building a list of associated values, referred to as an "array". If you are unfamiliar with arrays, have a look at the default .info files that come with Drupal and read the explanations of the examples that follow. Even though the .info file extension is not natively opened by an Application, you can use TextEdit on a Mac or Notepad on a Windows computer in order to view, edit, and save your changes.
Note that this page describes .info files used for Drupal themes, and not modules. For information about the structure of .info files for Drupal modules, see Writing .info files in the Module developer's guide.
The following example shows the Drupal 6 .info file for the Garland theme:
name = Garland
description = Tableless, recolorable, multi-column, fluid width theme (default).
version = VERSION
core = 6.x
engine = phptemplate
stylesheets[all] = style.css
stylesheets[print] = print.css
Theme name requirements
The name should start with an alphabetic character, can contain numbers and underscores, but not hyphens, spaces or punctuation. The name will be used by Drupal in forming various functions in PHP and therefore it has the same limitations. Warning! Do not choose the same name as a module, as all installed components must have unique names. For locally created themes using a prefix that is likely to be unique is good for theme naming. A site example.com might call its themes ex_themename.
Because the .info file is cached, you must clear the cache before any changes are displayed in your site.
The .info file can also specify which theme settings should be accessed from the Drupal administration interface, as you will soon see.Read more