When using the different catalogs to verify locations you can cut and paste found information into the ILL form if desired. Highlight call number, location, shelf status, etc. by holding down the left button on your mouse and sliding over all pertinent information. Go to menu bar, highlight edit and click on copy. Go back to the ILL form, place cursor in the big box window. Go to menu bar, highlight edit and click on paste.
Information is now there.
To add more catalog information from other libraries, be sure to place your cursor after previously pasted information.