Tags are text slugs stored in the
Tags Article of the Metadata namespace of a ZIM file.
A ZIM file can have zero, one or many Tags.
Should there be more than one, those are separated by the
Tags are used by publishers to classify ZIM files.
Tags should help represent, classify or identify a ZIM. ZIM readers are responsible for making use of Tags or not.
Tags are commonly displayed to reader users at ZIM-selection stage and not when using a ZIM file.
Tags are free text and can thus contain any UTF-8 character except for the
; separator. It is common to restrict Tags to single or two-words combination. Concision is important for users to remember and identify content.
Any Tag starting with the
_ (underscore) character is considered a private tag. Private tagging is a convention and nor par of the specification.
Private tags are usually hidden by readers and used as flexible metadata.
Common private tags used by kiwix Publishers:
_ftindex: indicates that the ZIM file includes a full-text index.
_pictures:<no|yes>: indicates whether the ZIM file includes pictures.
_videos:<no|yes>: indicates whether the ZIM file includes videos.
_details:<no|yes>: indicates whether the ZIM file includes detailed content.
_category:<xxx>: indicates that the ZIM file could be categorized as
ZIM readers don't have to follow this convention. Kiwix readers don't even use the
_category Tag in readers but uses it to inform its separate filtering mechanism.