Littelfuse

A label says XrefBase has published that kind of relationship for the part, and how many. Replacement means the part has a published replacement; Predecessor means it replaced an older part. A part with no label has not been assessed yet — not assessed and found to have no alternative.

ReplacementAsserts substitution

Published replacements. The only results asserting a replacement relationship. Confirm application-specific fit before use.

FunctionalNot a substitute

Functional equivalents. Similar function, not a confirmed drop-in. Engineering review is required before substitution.

Same seriesNot a substitute

Same series. Same family, different configuration. Family navigation, not a substitution claim.

VariantNot a substitute

Variants. The same part in a different keying, colour or packaging suffix.

PredecessorNot a substitute

Superseded predecessors. Product history, shown for context only — not an alternative to this part.

Mates withNot a substitute

Mating counterparts. What this component plugs into. These are never substitutes for it.