Namespaces — meaning

Genus name Species name commonly
Homo sapiens human
Picea glauca white spruce
Agoseris glauca prairie agoseris
Pilosocereus leucocephalus a fuzzy cactus with a pretty pink/red flower
Haliaeetus leucocephalus bald eagle
TEI head a heading, e.g. of a chapter
HTML head container for metadata
TEI constraint a formal constraint (e.g., in ISO Schematron) not expressed in the structural content model
DocBook constraint a constraint in an EBNF production
Introduction to Writing ODDs, slide 20 of 24