The different meanings and applications of the terms used to describe important taxonomic characters and to distinguish some species, genera, and families of Phaeophyceae are discussed. The position of reproductive structures on the thallus of crustose brown algae is considered a critical character but has been misapplied or interpreted differently by some investigators. The meaning of the terms “lateral” and “terminal” sometimes varies as used by different authors, as does the usage of “paraphyses” and “stalks.” For example, the position of the reproductive structure, lateral vs. terminal, and its relative position to the paraphyses, reproductive or vegetative filaments, and stalks have often not been clearly stated or defined. We propose restricted meanings and specific definitions for these terms in order to standardize their usage in algal systematics, and to simplify their use in comparative tables, numerical taxonomy, and morphological and phylogenetic analyses, etc.