Introduction to Signatures

This article is for teachers.

What are Signatures?

Signatures form the basis for allowing or filtering traffic within the school network. Signatures can contain websites, applications, games, search keywords, IP addresses, ports and groups of websites. 

These are the types of Signatures you’re most likely to see when managing your class:

Website signatures

Website signatures refer to website domains and subdomains. A domain is a website’s name and is what follows the “@” in an email address. It comes with an extension, such as “.com”, “.net”, “.org” and others in a URL.


This means that if you make a rule using a Website Signature, it will apply to all of the individual pages in that website. For example, setting an Allow rule for the Google Signature will let the students access,, and similar pages under the domain. Blocking the Google Website Signature will stop students from accessing any Google page.

You can also add Classwize rules for desktop versions of website signatures. For example, adding a Blocked rule for the signature Spotify will block both the Spotify Web Player and the Spotify app for Windows devices.

Rules for desktop versions of website signatures are only available to Connect for Windows.

Application signatures

Application Signatures refer to desktop applications. Also called App Controls, this signature currently supports Windows-only applications, such as Notepad, Paint, and Windows Media Player, as well as Windows versions of the most common computer apps, such as Microsoft Word and Adobe Reader. Check our list of Windows applications included in App Controls.

Rules created for this signature only apply to the apps on Windows devices and not their website versions. For example, a Blocked Rule for Microsoft Word will stop students from opening Word on their Windows devices, but not from opening Word on

Group signatures

Most websites need other websites in order to work properly. With very popular websites, we’ll create one Signature that includes both the website and all of the other sites it needs to work, such as embedded content and applications. We call these Group Signatures. Group Signatures let you create an Allowed rule on a site without worrying that some of its components won’t work.

A good example is the Mathletics group signature. If you created a rule that only Allowed the website, it might not work correctly. This is because uses content and services provided by two other websites: and These websites can be blocked individually by your school. While you could create rules that allow those websites, it’s easier to use the Mathletics signature to allow (or block) all three at once.

Themes and Categories

We classify each website into Themes and let you create rules that apply to every single resource in that theme. For example, websites and apps such as Facebook, Tiktok and Twitch all belong in the Social Media theme. By blocking (or allowing) access to Social Media, you can stop your students from accessing all sites and apps that belong in this theme.


Themes can also contain Categories. For example, a very broad theme called Arts and Entertainment contains several Categories: Animation and Manga, Celebrities and Entertainment, Music and Audio, Sports, and Streaming Media. Each of these categories contain Signatures.

You can create rules on themes and categories, as well as individual signatures. A rule that applies to a theme will also apply to its categories, as well as all the signatures under each category.

While a rule is in place for a theme, you can’t add a different rule for its categories or signatures. You can only exempt a category or a signature by adding its rule first. See Rules Validation Overview for more information on how Classwize checks if new rules are valid.

Game signatures

We’re not saying it’s hard to stop kids from playing Among Us, but… it’s hard to stop kids from playing Among Us. Or Fortnite, or Roblox or whatever other game is the current flavor of the month. There are often multiple ways to access these games, and so we create specialized Game Signatures that let you Block—or Allow— those games everywhere they can be played.

TIP: Using Classwize Reporting Tools helps you create better Rules
Students are very resourceful, especially with game unblockers. If you think you have students who are using a game unblocker, you can create a Screenshot History report to save the screenshots and URLs of these unblockers and forward them to your school’s IT support for further investigation.


Can I exempt a category from the rule for its theme?

Yes, by adding the rule for the category first. If there’s an existing rule for the theme, delete that rule and then add the rule for the category. For example, if you want to allow the category, Music and Audio while blocking its broader theme, Arts and Entertainment:

  1. Delete the Blocked rule for Arts and Entertainment.
  2. Add an Allowed rule for Music and Audio.
  3. Add the Blocked rule for Arts and Entertainment.

Your students will be able to access the signatures under the Music and Audio category, but not the signatures under Streaming Media or Sports. 

Similarly, you can exempt a signature from the rule that applies to its category. To exempt a signature, you must add its rule first before adding the rule for its category.

Can I restore the rules for themes or categories?

You can restore the rules you’ve just deleted by adding them again. Restored rules will apply to all categories and signatures within the theme but not to the ones you’ve exempted.


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