The Cabinet discussed the issue of security responsibility for the 'Jerusalem envelope' and for the seam zone.
(Quoted from: Cabinet Communique - Apr 30, 2006 12:43:57 Information Department, Israel Foreign Ministry - Jerusalem)
Envelope is their translation for the Hebrew word "otefet" or "ma'atefet" which I would claim should be translation better as "wraparound" which has as a definition: shaped to follow a contour and that is what the fence does.
It is not an envelope even though the verb, to envelop means: to enclose or enfold completely with or as if with a covering.
Most people might visualize placing Jerusalem in an envelope and that wouldn't be the impression we'd like to convey.
Come one guys and gals in the Foreign Ministry, let's use better language. At least that if everything else isn't going that well on the diplomatic front.