There are 5 transcriber-defined typeform indicators and 7 transcriber-defined symbol indicators. The typeform indicators are to be used for print fonts (red, highlighting, etc) the symbol indicators are to represent actual print symbols that there are no UEB indicators for.
If the book you are transcribing requires more than 5 transcriber-defined typeform indicators you will have to be creative...for instance, if there are no bold words in the text, it is acceptable to use bold (or script or underlining) for, say, the nouns (or whatever). Though it is not technically correct to use the transcriber-defined symbol indicators to represent a font, it would be better to use symbols that already exist in UEB than to create your own symbols.
BF does not create or change UEB symbols...we used only what was already defined/explained in the UEB rule book. We also did not "take out" any UEB symbols.