A locational clause (a cover term) is a predlocative clause or an existential clause.
The term is used in this way in Haspelmath (2025: 18). Hengeveld (1992: 94) uses "localizing (predicate)" in the sense of a locational clause. The term "locational (clause)" was used prominently by Clark (1978) as a cover term both for locational clauses (including predlocative and existential) and for possessional clauses (including appertentive and predpossessive) (in Haspelmath 2025, the cover term for these four is "locopossessional").
location clause (CXN) = a clause in which a locative relation is expressed, either predicationally or presentationally. These two types of location clauses are locative predication and presentational locative, respectively. (Section 10.4.1)