In the 'fcl-hash' & 'fcl-css' dirs I have found many lines which raise the exception. Like this `raise Exception.Create('20220428160853');` I suggest to add special class for hash-related exceptions / css-parser exceptions. To catch such errors by checking the exception-class. In fcl-css, such classes exist: ``` ECSSException = class(Exception); ECSSScanner = Class(ECSSException); ``` but are not used everywhere. it's OK?