BRING vinegar to a boil in a medium saucepan. Remove from heat and add mustard seeds. Cover and let stand at room temperature until seeds have absorbed most of the moisture, about 1-1/2 hours.
PREPARE boiling water canner. Heat jars and lids in simmering water until ready for use. Do not boil. Set bands aside.
COMBINE mustard seeds and liquid, water and Worcestershire sauce in a food processor or blender. Process until slightly grainy. Add cranberries and blend until chopped.
BRING cranberry mixture to a boil in a medium saucepan, stirring constantly. Reduce heat and simmer for 5 minutes, stirring frequently. Whisk in sugar, dry mustard and allspice. Continue to simmer, stirring frequently, until volume is reduced by a third, about 15 minutes.
LADLE hot mustard into hot jars leaving 1/4 inch headspace. Remove air bubbles. Wipe rim. Center hot lid on jar. Apply band and adjust until fit is fingertip tight.
PROCESS in a boiling water canner for 10 minutes, adjusting for altitude. Remove jars and cool. Check lids for seal after 24 hours. Lid should not flex up and down when center is pressed.