CHANGELOG.txt in Unique field 6

/**
 * Revisions log for unique_field
 */

version 2010/12/23 (6.x-1.4)
-- fixed settings form validation logic [thanks to etomilin]

version 2010/11/20 (6.x-1.3)
-- improved code checks to prevent warnings
-- added documentation through hook_help

version 2010/01/20
-- validation is skipped when a node is deleted (otherwise nodes
  with duplicate values are prevented from being deleted)
-- added support for taxonomy terms as content that must be unique
-- fixed translatibility of all strings
-- improved coding compliance

version 2009/11/12 (6.x-1.2)
-- added Italian translation [thanks to eliosh]
-- improved user message that reports duplicate values when checking
  fields in combination
-- fixed support for datetime and other date-related database field
  datatypes [thanks to Parkes Design]
-- added permission that allows users to bypass the unique field
  requirements after getting the warning message [thanks to benjah]

version 2009/03/06 (6.x-1.1)
-- fixed query generation for grouping OR clauses

version 2009/03/06 (6.x-1.0)
-- altered appearance of unique fields settings on the content type form:
  moved unique field section to the bottom, added descriptions
-- fixed compatibility with date module version 6.x-2.0
-- fixed compatibility with content_permissions module [thanks to skassam]
-- Hungarian translation added [thanks to Zoltan Balogh]

version 2009/02/09 (6.x-1.0-beta2)
-- improved handling of CCK values in single node scope
-- fixed formatting bug in duplicate error message

version 2009/02/07 (6.x-1.0-beta1)
-- fixed handling of multiple values per CCK field
-- added option for showing the nodes that match when a duplicate
  value is found [thanks to crea]
-- added node language as a query field and scope
-- fixed handling of node revisions
-- rewrote query generation routine
-- added node author as a query field
-- added hook_uninstall support for removing the module's variables
  [thanks to markus_petrux]
-- improved compliance with coding standards [thanks to deekayen]

version 2008/10/24
-- updated to compatibility with Drupal 6.x [thanks to Yur]
-- added check for content.module for CCK-dependent code [thanks to sigsby]
-- removed all MySQL database-specific code [thanks to rssaddict]

version 2008/03/15
-- fixed to use node title label from node type data [thanks to tj2653]

version 2008/03/14
-- changed behavior so that if a field value is null or empty it matches
  no other node (including other nodes with null or empty values)
  [thanks to scedwar]

version 2008/03/13
-- fixed support for node and user reference fields in single node scope,
  verified support for both in other scopes

version 2008/03/12
-- added single node scope to require that specified fields on a node
  have unique values
-- improved error messages to specify which fields must be unique
  and which include duplicates

version 2008/02/22
-- fixed queries to support table prefixes

version 2008/02/18
-- initial release

TO-DO
-- add SimpleTest test
-- fix consistent case-sensitivity of database queries, add option
  for whether to use case-sensitive comparisons (see #333137)
-- add validation before submission via AJAX (see #338744)
-- add views as a query scope (see #223792)
-- allow multiple types of constraints (see #347327)