%WIKITOOLNAME% allows to define some restrictions of who is allowed to make changes and attach files to topics.

**IMPORTANT NOTE:** Is is recommended to use the access control feature only if absolutely necessary because it goes against the free [[WikiCulture]], where everybody is invited to contribute to any topic.

**_Users and Groups_**

Access control is based on users and groups.

**_Users_** are defined by the user topics in the %MAINWEB% web, i.e. %MAINWEB%.TWikiGuest

* Users can be authenticated using basic authentication or SSL. [Installation Notes](TWikiDocumentation#installation) has more.

**_Groups_** are defined by group topics in the %MAINWEB% web, i.e. %MAINWEB%.TWikiAdminGroup

* A group topic name must end in **...Group**
* The group topic should define these two variables:
  * Set GROUP = < list of users and groups >
  * Set ALLOWTOPICCHANGE = < list of users and groups >
* GROUP defines the members of the group; it is a comma delimited list of users and other groups. Example: <br /><code>    \* Set GROUP = %MAINWEB%.SomeUser, %MAINWEB%.OtherUser, %MAINWEB%.SomeOtherGroup</code>
* ALLOWTOPICCHANGE defines who is allowed to change the group topic; it is a comma delimited list of users and groups. You typically want to restrict that to the members of the group itself, so it should contain the name of the topic, i.e. <br /><code>    \* Set ALLOWTOPICCHANGE = %MAINWEB%.TWikiAdminGroup</code><br /> for the TWikiAdminGroup topic. (This is to prevent users not in the group from editing the topic and gaining unauthorized membership to the group.)

**_Access Control for Individual Topics_**

You can define some restrictions of who is allowed to make changes and attach files to a topic.

Define one or both of these variables in a topic, preferably at the end of the topic:

* Set DENYTOPICCHANGE = &lt; list of users and groups &gt;
* Set ALLOWTOPICCHANGE = &lt; list of users and groups &gt;

DENYTOPICCHANGE defines users or groups that **are not** allowed to make changes to the topic. It is a comma delimited list of users and groups. Example: <br /><code>    \* Set DENYTOPICCHANGE = %MAINWEB%.SomeBadBoy, %MAINWEB%.SomeBadGirl, %MAINWEB%.SomeHackerGroup</code>

ALLOWTOPICCHANGE defines users or groups that **are** allowed to make changes to the topic. It is a comma delimited list of users and groups. Example: <br /><code>    \* Set ALLOWTOPICCHANGE = %MAINWEB%.SomeGoodGuy, %MAINWEB%.SomeGoodGirl, %MAINWEB%.TWikiAdminGroup</code>

DENYTOPICCHANGE is evaluated before ALLOWTOPICCHANGE. Access is denied if the authenticated person is in the DENYTOPICCHANGE list, or not in the ALLOWTOPICCHANGE list. Access is granted in case DENYTOPICCHANGE and ALLOWTOPICCHANGE is not defined.

**_Access Control per %WIKITOOLNAME% Web_**

You can define some restrictions of who is allowed to make changes and attach files to topics or create new topics in a %WIKITOOLNAME% web.

Define one or both of these variable in the [[WebPreferences]] topic:

* Set DENYWEBCHANGE = &lt; list of users and groups &gt;
* Set ALLOWWEBCHANGE = &lt; list of users and groups &gt;

The same rules apply like the one for Access Control for Individual Topics; with these additions:

* DENYTOPICCHANGE (in topic) overrides DENYWEBCHANGE (in WebPreferences)
* ALLOWTOPICCHANGE (in topic) overrides ALLOWWEBCHANGE (in WebPreferences)

**_Related topics:_** [[TWikiPreferences]], [[WebPreferences]] (in every web), %MAINWEB%.TWikiAdminGroup

-- [[Main/PeterThoeny]] - 28 Oct 2000 <br />