Pottery and porcelain marks
Countries like England created the Design Registration System and in the United States, marking requirements for the country of origin begin with the McKinley Tariff Act of 1891. Unlike silver, there is no formal system for marking pottery and porcelain. Fortunately, there are many good books that show various manufacturers marks. They are typically indexed by the type of image they use, bird, anchor, flower, etc.
J. P. Cushion who was the Senior Research Assistant at the Victoria and Albert Museum in London, published a an excellent marks book called The Handbook of Pottery and Porcelain Marks. In addition to pottery and porcelain marks for 20 different countries, there is an appendix which shows the registered design owners based on the date and parcel number. The book was last published in 1996. Used copies are very reasonably priced through on-line book sellers.
A Manual of Marks on Pottery and Porcelain, a Dictionary of Easy Reference was first published in 1898 by W. H. Hooper and W. C. Phillips. Since the copyright is expired, we have provided a pdf to use as a reference. The file will download when you select this link: A Manual of Marks
After the file downloads, double-click on it and it will open, or right-click and select "open". You may then save it to your computer for future reference.