A Tutorial Library That Separates Prerequisites From Optional Background Without Looping

A tutorial library often links articles to each other with one vague phrase: related reading. Readers cannot tell what they must read first from what is merely interesting, and editors can accidentally create loops where A requires B and B requires A. This article proposes a small relationship register and a pre-publication check. All samples are hypothetical, not observed client results.

The artefact: a relationship register

One row per link:

From tutorial.
To tutorial.
Type: prerequisite or background.
One sentence on why, written for the reader.

Sample library for an imaginary spreadsheet course: Entering data, Formatting cells, Writing a sum formula, Building a summary table, History of spreadsheets.

Writing a sum formula requires Entering data (prerequisite).
Building a summary table requires Writing a sum formula (prerequisite).
Building a summary table has Formatting cells as background (optional).
Entering data has History of spreadsheets as background (optional).

Rules that keep it honest

A prerequisite means the tutorial assumes a skill or step from the other one. If a reader could succeed without it, it is background.
Prerequisites point earlier in the path; background may point anywhere.
Only prerequisites form the learning order. Background links never block anything.

Cycle check

Before publishing, walk the prerequisites only. Start from each tutorial and follow its prerequisites; if you return to the starting tutorial, there is a cycle. By hand, for a small library, list each tutorial and its prerequisite chain on paper. A cycle usually means one link is really background, or two tutorials should be merged or split.

Decision branches when a cycle appears

If one of the two links is only helpful, change it to background.
If both are genuinely required, the shared material probably belongs in a third, earlier tutorial. Create it and point both at it.
If neither fix is sensible, do not publish the new link. Leave the tutorials unlinked and note the problem for review.

Presenting it to readers

On each tutorial page show two labelled blocks: Before you start (prerequisites, with a short reason each) and Optional background (background links). Hide an empty block rather than showing a heading with nothing under it. Do not mark background links as steps or number them.

On a library index, you may offer a suggested order built from prerequisite chains. Say it is a suggestion; a reader with experience may skip ahead.

Stop conditions

Do not publish a prerequisite pointing to an unpublished tutorial.
Do not auto-generate a path through background links.
If a prerequisite chain grows long, consider whether a tutorial is trying to teach too much.

Practical acceptance test

With the sample library:

Open Building a summary table. Expect Before you start to list Writing a sum formula, and Optional background to list Formatting cells.
Open History of spreadsheets. Expect no Before you start block.
Add a deliberate bad link: Entering data requires Building a summary table. Run your chain walk from Entering data. Expect to detect the return to Entering data and refuse to publish.
Change that link to background. Expect the chain walk to pass.
Unpublish Writing a sum formula in staging. Expect the register check to flag Building a summary table's broken prerequisite.
Read the suggested order. Expect Entering data first and no background-only tutorial inserted as a step.

Conclusion

Two link types, one reason sentence each, and a short chain walk give readers a clear entry point and prevent circular paths. The check is small enough to do by hand for a modest library.