This template is used on approximately ୨,୩୦,୦୦୦ pages. To avoid major disruption and server load, any changes should be tested in the template's /sandbox or /testcases subpages, or in your own user subpage. The tested changes can be added to this page in a single edit. Consider discussing changes on the talk page before implementing them.
Multi-year seasons/office terms/numerical ranges are acceptable as long as the duration/range size remains constant, and no years/numbers are irregularly skipped. The length of each duration/range is automatically determined from the originating category name, up to and including 10 years. compliance is preferred, but some deviation is allowed and tracked. {{Category redirect}}s are followed, and tracked for either MOS contravention (to be corrected) or for navigational aid (no error). The gap size between successive durations/ranges is also automatically determined, up to and including 5 years if a surrounding category is found, and defaults to 0 (e.g. 1995–96 → 1996–97).
Automatically condensed year display is supported for presidential categories only (but can be easily expanded as needed), for gaps up to and including 5 years, and defaults to 1. To skip gaps up to 10–15 years (position-dependent) in any year categories, use |skip-gaps=yes.
Ordinal words do not work above the ninety-ninth, because no higher working examples were found.
General: for large, permanent gaps between successive categories, or when the base category name changes, use {{Category pair}} in addition to {{Navseasoncats}} on both sides of the gap/name change. Even if {{Navseasoncats}} is isolated, it has the benefit of confirming the absence of nearby categories to the reader or maintainer.
Which is technically an inappropriate category for {{Navseasoncats}} placement, but it best shows the |list-all-links=yes behavior for all element variants (blue, red/grey, hidden, and redirect), and would otherwise display as: