MediaWiki headers may match a general element filter in subscriptions, and therefore be collapsed automatically.

• Wikipedia

• Any other websites using MediaWiki wiki software

MediaWiki automatically assigns ids to headers according to their content, which means that the header Example would also have an id of Example or, in CSS form, would be matched using the selector #Example. While not normally an issue, some general element hiding filters from subscriptions, such as ###Advert, may match the header text, and therefore hide the titles due to their identical ids.

As the consequences of this issue are minimal, only collapsing a title, and only then if it matches one of the general element rules from the subscription, the problem will not be resolved in EasyList. The only method to resolve the issue effectively is to use the filter @@||wikipedia.org^$elemhide, although it will also prevent such rules being used to collapse their fundraising banners, another reason why the problem was not resolved in the subscription.