Comment Signature Filter

This filter removes blocks of HTML code enclosed between start and end comments. It may be used to remove server-side spyware code (like RedSheriff, WebSideStory, etc.), blocks of ads, etc. This filter is similar to two other signature filters: Text Signature Filter and Script Signature Filter.

The filter will delete everything after the opening comment containing unique keywords until the closing comment. If there is no closing comment, at least one HTML element is deleted. The opening comment must start with on of the signature strings, or someting like “start”, “start of”, or “begin” followed by a signature string. The rest of the comment does not matter. The rules for closing comments are similar to those for opening comments.

Signature matching is case-insensitive, and matches whole words only, e.g. foo bar will match foo bar baz but not foo bars.

For example, if you specify RedSheriff as a signature, any of the following comments will be recognized as opening comments:

<!-- START RedSheriff Measurement V5.01 -->
<!-- Start of RedSheriff Measurement -->
<!-- Begin RedSheriff code -->
<!-- RedSheriff (the rest does not matter)-->

Some examples of closing comments:

<!-- END RedSheriff Measurement V5.01 -->
<!-- End of RedSheriff Measurement -->
<!-- /RedSheriff code -->

Note: The same effect can be achieved with an External Filter running a simple awk script, which might be more flexible. The main difference is the speed; external filters are much slower. Besides, unlike external filters, which work with raw text, internal HTML filters work with a stream of HTML tokens, so they are more reliable (for example, this filter will not match comments inside JavaScript string literals).

Parameters

string

One or more string parameters define a set of string signatures to look for in comments.

Format:

string = text

See also Common Filter Parameters.

Example

type = Comment Signature Filter
name = Stats Analyzer Killer
enabled = true
include = *
string = WebSideStory
string = RedSheriff
string = RedMeasure
string = SuperStats
string = Web-Stat
string = Data Collect
string = FastCounter
string = Vibrant Media