trademark -
a formally registered symbol identifying the manufacturer or distributor of a product
marker,
marking,
mark some conspicuous object used to distinguish or mark something; "the buoys were markers for the channel"
sharpie a shallow-draft sailboat with a sharp prow, flat bottom, and triangular sail; formerly used along the northern Atlantic coast of the United States
trademark A word or mark that distinctly indicates the ownership of a product or service, and that is legally reserved for the exclusive use of that owner.