The J Phrases book contains a wealth of useful J idioms. It is no longer being maintained actively, and there is an ongoing project to move phrases from the book to the appropriate subpages of Phrases. You can help in this effort.
When you move a line, make sure you add calling syntax, if appropriate, and delete the line from the J Phrases book.
Please also verify that the phrase is valid in J6. There have been minor language changes over the years that require corresponding changes in the Phrases.