{COMMENTADMIN} - If viewer can edit the comment, contains linked image to do so... otherwise empty.
{COMMENTTYPEOPTIONS} - Contains the options for selecting the comment type.
{COMMENTDATE} - Date on which comment was posted.
{COMMENTLASTEDITDATE} - Date on which comment was last edited.
{COMMENTID} - Id number of the comment.
{COMMENTURL} - The URL to the comment in the thread.
{COMMENTICONIMAGE} - The post icon image HTML.
{COMMENTLINKID} - Id number of the article which the comment is about.
{COMMENTLINKNAME} - The title of the article which the comment is about.
{COMMENTPOSTERNAME} - Name of the poster.
{COMMENTMESSAGE} - The actually comment text.
-- Optional parameters: {COMMENTMESSAGE[x]} cuts off the text after x characters. {COMMENTMESSAGE[x <,> option]} - "option" can be either "remove" to remove all quotes and wsn codes from the comment, or "docodes" to parse the codes and smilies. Not using the parameter defaults to not parsing the codes but not removing them either.
{COMMENTIP} - The IP address of the comment.
{COMMENTIPCITY} - The city the IP address is located in, if geolocation is enabled.
{COMMENTOWNERID} - The member id number of the member who owns the comment.
{COMMENTTYPE} - The comment type of this comment.
{COMMENTAPPROVED} - Number of people who have approved of the comment.
{COMMENTDISAPPROVED} - Number of people who have disapproved of the comment.
{COMMENTPERCENTAGE} - The percentage of voters who approved.
{COMMENTVOTES} - Total number of respondants rating a comment
{COMMENTNUMBER} - The position in which the comment appears in the thread.
{COMMENTCATID} - The id number of the category the comment is in.
{COMMENTISNEWSINCELOGIN} - Determines if this has been added since the viewer logged in.
{COMMENTISMODERATED} - Checks whether the comment has been moderated by anyone in any way (editing, deletion).
{COMMENTDELETEDBYNAME} - The name of who deleted the comment, if applicable.
{COMMENTQUOTELINK} - A link to quote the post. Introduced in version 9.0.0.
{COMMENTHOSTNAME} - The host name associated with the IP address of the comment submitter.

Category and article template variables can be used and will reflect the category/article the comment is associated with.