Marker

Marker may refer to:

• Marker pen, a felt-tipped pen used for drawing and/or coloring
• Marker (linguistics), a morpheme that indicates some grammatical function
• Marker (telecommunications), a special-purpose computer
• Marker, a set of sewing patterns placed over cloth to be cut
• Marker or Clapperboard, equipment used during filming
• Paintball marker or paintball gun, an air gun
• Biological marker, or biomarker, a substance used as an indicator of a biological state
• Genetic marker, a DNA sequence with a known location associated with a particular gene or trait
• Historical marker, a plaque erected at historically significant locations
• Survey marker, an object placed to mark a point
• Boundary marker, an object that identifies a land boundary

https://en.wikipedia.org/wiki/Marker