Most sites do not mind if users have adblocking software installed in their browser. There are however a couple of sites that take counter measurements, trying to convince users to disable their adblockers. Our policy states the following about those so-called anti-adblock measurements: "Anti-Adblock should only be challenged if the system limits website functionality or causes significant disruption to browsing". Since this can be interpret in numerous ways, here's a more detailed explanation for webmasters about what we allow or disallow.

This is what we allow and/or require from anti-adblock measurements:

• It must use small, static images and/or text only.
• The font and markup must be similar to the other parts of the page.
• The text must be polite and understandable, or at least in the same tone as the other parts of the website.
• It must be clear that the message is shown because the user is using adblocking software.
• It must not interrupt the normal reading flow of the page content.
• It must be clear that any action requested in the anti-adblock message, like disabling the adblocking software, whitelisting your site or asking a donation as a replacement for the ads, is completely voluntarily.
• It may suggest disabling adblockers entirely, but if it does, it must also include detailed and easy-to-read instructions to disable them on your domain only.
• When the user clicks an anti-adblock message, more content may be shown (including overlays, animated images and all otherwise forbidden content types, like plugins), provided they can be closed.
• The user must be the only one in control of the filters required for the purpose of the anti-adblock message. It must not be possible for external sources to add, modify or remove any rules remotely.

This however is what we do not allow:

• Animations (including changing text messages), sounds and other content that will constantly distract the user.
• Content that uses plug-in resources or frames.
• Redirects (automatic page forwarding) and pop-ups to a different page.
• Content that overlaps the normal page content or prevents the normal reading flow in any other way, like messages in the middle of a text.
• Content with a height over 100px and a combined area larger than 105,000px. This includes the size of unnecessary empty areas caused by the message.
• Content for which it is not immediately clear it's targeted to users of adblocking software.
• Measurements that limit the access to the site and/or cause annoying side effects (like additional delays) and/or prevent normal content to be shown.

Well, that isn't too hard, is it? If you follow these guidelines, we're all happy. We (the list authors), because we don't have to add or adjust rules for your site. The visitor, because (s)he won't be the victim of terrible anti-adblock measurements. And the site admins, because they don't have to adjust their site every time we block their message, while still being able to tell users about their adblockers.

There are just two more side notes that should be mentioned:

• If your anti-adblock message does not follow the guidelines, or there is discussion about its compliance, it is up to the list author(s) to determine if we block it or leave it as it is. When your anti-adblock message is being blocked specifically, while it's following all guidelines, please leave a notification in our forums or send an email to our email address; if we agree, it'll be unblocked.
• In case your anti-adblock message is being removed by a filter that is also used to block or hide ads or other content that should be blocked anywhere else, it will not be whitelisted, even if you perfectly follow all guidelines.