Agriculture
May 1986, wide dies
Picture from Dave Hoag

This type is Vermont's basic farm plate. Usually seen on farm trucks, but sometimes seen on other things such as florist's vehicles. For wide dies, they started at A1000.
July 1987, wide dies
Collection of the author
November 1988, wide dies
Collection of the author
July 1996, narrow dies
Picture from eBay

Upon switching to the narrow dies, numbering began in the AAA 000 format. So far, I have only seen them in the AAx series.
March 1999, narrow dies
Collection of the author
September 2003, narrow dies
Collection of the author
September 2005, narrow dies, new style sticker
Photographed in use
Undated, narrow dies
Collection of the author

I've never seen an agriculture vanity plate in use, but I think you can get just about any type of Vermont plate in vanity format if you ask.