I prefer "已存放图则".

虽然 plan 也可翻为 “计划”，但是在建筑 (建地) 上更常译为 “图”，例如:

Space plan:空間平面圖
Site plan:工地平面圖
http://www.hklii.org/hk/legis/en/ord/374/s122-30061997.html


請參考以下解釋:
“已存放圖則”(deposited plan) 指根據第123條擬製及存放的圖則，包括根據該條以更改現有圖則的方法而擬製及存放的任何新圖則”

http://www.legislation.gov.hk/BLIS_IND.NSF/b505654fa2fd062b4...
香港《立法會決議》(2007年第130號法律公告)


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Note added at 1 hr (2009-07-06 13:07:48 GMT)
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Correction:

"已" is not necessary in the context.

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Note added at 1 hr (2009-07-06 13:11:15 GMT)
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In the context, "编号" can be added.

So, "存放图则编号" would be more complete.

Please see the following denifition:

A deposited plan (DP) is the plan number given to a subdivision that is registered by the Land Titles Office.

http://www.pittwater.nsw.gov.au/building__and__development/g...