When I buy and read "The Ultimate Resource for Perl 5 Professionals! The most complete, concise reference available...", I expect the kind of detail that eliminates the need for additional Perl 5 reference books and the need to exhaustively test exactly how functions work. One simple example: gmtime takes a single date/time argument and returns 9 individual date and time variables, but this book doesn't provide details about the values returned in those variables. Is the month represented as 1 to 12, or 0 to 11, for example? It's up to the reader of the book to figure that out. Not hard to do, but it greatly diminishes the value of the book when that level of detail is not provided.