tugi- ehk lähtemärk veepinna taseme ja maapinna reljeefi kõrguste mõõtmisel, term originates from the chiseled horizontal marks that surveyors made in stone structures, into which an angle-iron could be placed to form a "bench" for a leveling rod, thus ensuring that a leveling rod could be accurately repositioned in the same place in the future, märk nivelleerimisel määratud kõrguse tähistamiseks (nt reeper), figure, letter, or typographical symbol used in indicating a cross-reference, or referring to a footnote or endnote