Item IDs in Cirrus

Every item in Cirrus has a unique Item ID generated automatically from a collection-level prefix and a counter. The full internal form also encodes the item's version and revision. Use this article to understand the format, the prefix, and how Cirrus sorts and counts IDs.

Format

The Cirrus Item ID has this internal structure:

CollectionPrefix-CollectionCounter.Version.ItemRevision

Authors usually see only CollectionPrefix-CollectionCounter (for example HVCA-445). The version and revision components appear in deeper views (item history, audits). See Item revisions and item versions for what each component means.

Highlights:

• The prefix is author-customisable on the collection.
• The Item ID is searchable and must be unique tenant-wide.
• The External ID is a separate, editable identifier on each item, for use by integrations.

The prefix

The prefix is the customisable part on each collection.

Rules:

• Prepended to every Item ID in the collection.
• Must be unique across every collection on the tenant.
• Allowed characters: uppercase Latin letters A-Z and digits 0-9.
• Can start with a digit.
• Minimum length 1, maximum length 10.
• Changing the prefix re-generates IDs across the collection's items.

Authors can change the prefix any time, but a change rewrites every existing Item ID in the collection, so do it deliberately.

The counter

The counter starts at 1 on each collection and increments by 1 every time a new item is created. It is not reset when items are deleted: the next item still takes the next counter value. Example: HVA-1, HVA-2. Deleting HVA-1 does not free that number; the next new item is HVA-3.

Sorting

Cirrus sorts Item IDs as text strings, not as numbers. This affects the order on long lists:

For predictable sort order on large collections, pad numbers with leading zeros (QUESTION-001, QUESTION-010, QUESTION-100).

Version number

• Increments by 1 for each new version of the item.
• SOWISO Mathematical questions and Section items do not have versions.

Revision number

• Increments by 1 for each new revision within a version.
• SOWISO Mathematical questions and Section items always show revision 1.

See Item revisions and item versions for the difference between a version and a revision and when each is created.

Related articles

• Item revisions and item versions
• How to add and use items
• How to add and use collections
• Import items to a collection