Salesforce B2B Commerce API sizing blocks can support multiple API sizing requests in three ways:
When different entities are specified in the method invocation. For example,ccrz.ccServiceProduct.getProducts(ccrz.ccAPI.SZ_M, ccrz.ccAPI.SZ_L)will use the SZ_M sizing block for the product entity and the SZ_L sizing block for the related entities.
SZ_ASSC is used. This flag indicates that the associated entities should use the same sizing block as the primary entity. For example,ccrz.ccServiceProduct.getProducts(ccrz.ccAPI.SZ_M, ccrz.ccAPI.SZ_ASSC)will use the SZ_M sizing block for both the product entity and the related entities.
SZ_ASSC is not used. This flag indicates that the associated entities should use the default sizing block, which is SZ_M, unless otherwise specified. For example,ccrz.ccServiceProduct.getProducts(ccrz.ccAPI.SZ_M)will use the SZ_M sizing block for the product entity and the SZ_M sizing block for the related entities. Salesforce B2B Commerce and D2C Commerce Developer Guide,Data Sizing Conventions