Were Royal Navy patronage lineages official?

How official were these Royal Navy patronage lineages?

They were completely unofficial, but their relationships could be traced across careers and branches.

Michael Clapp and Philip Vian are offered as members of the same patronage lineage despite their different branches of service. Such connections could cross professional specialisms within the navy. The system is described as completely unofficial. Its informal character still permits the relationships to be traced through careers and professional influences.