The present invention provides aqueous polymer compositions containing one or more, or, preferably, two or more markers selected from a C1-C12 alkyl phenyl ether having a formula Ph(R2)m(OR1)n, wherein Ph is an aromatic ring containing group having from six to nine carbon atoms, R1 is a C1-C12 alkyl group, R2 is a C1-C12 alkyl group, m is an integer of from 0 to 5, n is an integer of from 1 to 3, and (m+n) is an integer of from 1 to 6. The markers are readily detectable, such as by mass spectroscopy, upon solvent extraction and separation from the aqueous polymer compositions, or from dried or cured coatings, film or layers thereof.