Meteg (or metheg, Hebrew מֶתֶג, lit. 'bridle', also gaya געיה, lit. 'bellowing', מאריך ma'arikh, or מעמיד ma'amid) is a punctuation mark used in Biblical Hebrew for stress marking. It is a vertical bar place under the affected syllable.
Read more about Meteg: Usage, Appearance and Placement, Unicode