This may occur when a taxonomist finds and recognises a taxon and thinks of a name, but delays publishing it in an adequate manner.
A common reason for this is that a taxonomist intends to write a magnum opus that provides an overview of the group, rather than a series of small papers.
Another reason is that the code of nomenclature changes with time, and most changes have retroactive effect, which has resulted in some names becoming invalid that the author thought were validly published.
This clear definition helped establish the foundational principle that valid publication is a prerequisite for any nomenclatural status.
This principle helps maintain clarity about when names are truly validly published versus when they are simply being recorded or referenced.
Names that satisfy the code but not found in these sources are effectively published as long as the journal is sufficiently recognized.
Two examples illustrate this process: when Thalassobius gelatinovorus was first proposed in 2005, it was published with only one type strain deposit instead of the required two.