Quantitative analysis of grain boundaries relies on proper boundary parameterizations. One of the approaches to identification of boundaries is the ‘interface-plane scheme’. A rigorous examination reveals that this approach is deficient. It is demonstrated that the ‘interface-plane scheme’ fails to satisfy necessary conditions for a parameterization. Moreover, the difference between boundaries symmetric in the conventional sense and those termed as symmetric in the ‘interface-plane scheme’ is clarified. Also the relationship of these boundaries to twist and tilt boundaries is analyzed. Revealing the unsuitability of the ‘interface-plane scheme’ for boundary parameterization and eliminating the confusion caused by the incompatible definitions of symmetric boundaries is of importance for the progress in analysis of homophase interfaces.