An unmarked term, in linguistics, is a word which refers to the broadest subset of specifics within a category. This distinction develops as a matter of common usage among the public, and accordingly is often identified with a dominant subset within a hierarchical phonology. For example, "man" is often used to refer to all human beings, even though it simultaneously refers to just males; this usage evolved thanks to masculine dominance of the phonological hierarchy, and is reflected in many other places as well. This principle also applies in the inverse, where the dominated subset is used as the label for generalities that are considered inferior ("stewardess" for all who serve passengers on a plane, for example).
Critics of many contemporary unmarked terms (such as deconstructionists) have pointed out an essential privilege to the group that was dominant within the phonological hierarchy when they developed - typically men - but defenders argue that, because the masculine form of words is also generally considered to be the gender-neutral form within the whole of the language, this reflects the essential utility and consistency of the practice, rather than a systemic bias. Accordingly, while such terms as "brotherhood of man" still identify all human beings rather than just males, there has been some shift in other terms, such as the increased use of the neutral term "flight attendant" rather than "stewardess."
Unmarked terms are very common, and marked terms are used only when context requires. For example, the notice "No dogs allowed" is always understood to contain an exception for seeing-eye dogs. Likewise, in the context of a daycare center "accident" refers to a toileting accident like wet pants (and "wet" in turn means urine rather than a water spillage).