Is it advisable to specially mark products which are patented or for which a patent application is pending?
In general, yes, in particular if the patented product is to be marketed in one of the following countries:

The United States of America, the United Kingdom, the Republic of Ireland, Denmark, Sweden, Taiwan, Australia.

In these countries the amount of damages able to be claimed in cases of an infringement depend in a decisive way upon the presence of a corresponding product marking.