I won't include myself in any expert list, but my idea of a withdrawal would be to discontinue selling it until further notice. I am thinking as in retail stores or even restaurants, you would remove that item from the shelves or menu.
A recall on the other hand would be an actual, pulling from the shelves and inventory anything that you have of that product and returning it to the manufacturer.
This is from CFIA's FSEP/HACCP program which is based on ISO 22000:...
"Product Withdrawal" means a firm's removal from further sale or use of a
marketed product that does not violate legislation administered or enforced by the CFIA. It is not considered to be a recall.
"Recall" (verb tense) means for a firm to remove from further sale or use, or to correct, a marketed product that contravenes legislation administered and/or enforced by CFIA.
"Recall" (noun tense) denotes the process of recalling the affected product and encompasses all tiers of the affected product distribution system.[FONT=Arial, sans-serif]
Hopefully this helps clarify things a little.[/FONT]
Mauri