Drupal Naming Conventions Cheat Sheet Chart & Summary

• CONSTANT_NAMES
• css-classes
• css-ids
• DOCUMENTATION.txt (!notice l.c. extension)
• filenames-in-general
• html_form_variables (since they convert to php variables)
• javascriptFunctions
• javascriptVariables
• mysql_columns
• mysql_tables (all tablenames should be singular, e.g. node)
• mysql_databases
• _php_global_variables (!notice leading underscore)
• _php_private_functions (!notice leading underscore)
• php_functions
• php_variables
• phpClassMethods
• PhpClassNames
• phpClassProperties
• query_string_variables (since they convert to php variables)
• url-paths

Sources:
http://drupal.org/coding-standards#naming
http://drupal.org/node/302199
http://drupal.org/node/172169
http://drupal.org/node/2497