If you are admin or if you have the proper permission you can use full HTML when you edit a Wiki page. Normally you don't want regular users to use HTML since they can use incorrect HTML, alter the page layout, or break pages. That's why the Wiki-Tag system exists. However, for admins or trusted editors full HTML editing is a powerful way to make a page look exactly as they want. Whenever you edit a page containing HTML code make sure that the Allow HTML checkbox is checked or the HTML tags will be eliminated. IF you accidentally destroy a page that previously contained HTML, don't worry. Just roll back the page to the previous version using the rollback button from the page history.

I am unable to include HTML in page. I get the following response
The following error message was returned:

Unknown column 'added_by' in 'field list'
The query was:

INSERT INTO `tiki_plugin_security` (`fingerprint`, `status`, `added_by`, `last_objectType`, `last_objectId`) VALUES(?, ?, ?, ?, ?)
Values:

html-d433e4b5f89a6fa8c5f4821b6fd19012-0df3f8fa6a273b5283894cce2d1e8455-332000-200000
pending
RVBelanger
wiki page
UserPageRVBelanger
The built query was likely:

INSERT INTO `tiki_plugin_security` (`fingerprint`, `status`, `added_by`, `last_objectType`, `last_objectId`) VALUES('html-d433e4b5f89a6fa8c5f4821b6fd19012-0df3f8fa6a273b5283894cce2d1e8455-332000-200000', 'pending', 'RVBelanger', 'wiki page', 'UserPageRVBelanger')

From chibaguy I have concluded that the table tiki_plugin_security does not have the column field added_by. I have confirmed that the table in question does not have field by using phpmyadmin. I have also looked at the other wiki sites I have set up and confirmed that their tables do include the appropriate field, which explains why they are working with html. I contacted siteground the host and asked them the question and they have pointed me back to this community. I am really puzzled by that because all 5 sites were set-up and installed the same way using their script and I have a very elementary understanding of SQL and PHP. I can see the table and field in phpmyadmin. Is it as simple as adding the field to the table and moving on? I do not see any place to just add the field. I can create a new table and add fields but i do not see where to add fields to an existing table. Can someone please provide direction.