This is a documentation subpage for Template:GBoldmap. It may contain usage information, categories and other content that is not part of the original template page.

This is an experimental template and is liable to change or withdrawal.

This template has been designed to be used within articles about demolished buildings or similar structures in Britain (that is, England, Wales or Scotland). It produces a list of links to historic maps that explicitly show the structure in question, before demolititon.

Example:

{{GBoldmap|53.766876|-2.691264|SD|5453|3028|Deepdale Station|
  MARIO 2500=(about 1893)|
  MARIO 10000=(about 1847)|
  Old OS Maps=(estimated 1925 to 1945)|
  NPE Maps=y|
  Vision of Britain=y}}

In this example:

• 53.766876 is the latitude in decimal degrees WGS84 datum (N);
• -2.691264 is the longitude in decimal degrees WGS84 datum. Negative for 'W', positive for 'E';
• SD are the letters for the Ordnance Survey grid reference;
• 5453 is the 4-digit eastings part of the OS grid reference (if you have fewer than 4 digits you should add zeroes to the right; if you have more than 4 digits you should omit the rightmost digit(s); do not omit zeroes on the left)
• 3028 is the 4-digit northings part of the OS grid reference (if you have fewer than 4 digits you should add zeroes to the right; if you have more than 4 digits you should omit the rightmost digit(s); do not omit zeroes on the left)
• Deepdale Station is the name of the building.

Each of the remaining parameters is optional, but you must include at least one. Each one specifies a map to be included in the list, and, optionally, some text to display after it.

• MARIO 2500 refers to OS 1st Ed 1:2,500 scale maps for selected urban areas of Lancashire on Lancashire County Council's MARIO website http://mario.lancashire.gov.uk
• MARIO 10000 refers to OS 1st Ed 1:10,000 scale maps for most of Lancashire on Lancashire County Council's MARIO website http://mario.lancashire.gov.uk
• Old OS Maps refers to http://www.ponies.me.uk/maps/osmap.html
• NPE Maps refers to http://www.npemap.org.uk
• Vision of Britain refers to http://www.visionofbritain.org.uk

In each case, the value to the right of the = sign will be displayed after the link. You can specify y or Y (for yes) to select a map without any extra text. To omit a map from the list, omit the relevant parameter.

In all cases, a link to the standard Wikipedia co-ordinates page appears at the bottom of the list.

The idea is that you should select only those maps which actually display the structure in question. Maps that are too old or too new may not show the structure and these should be omitted.

You, as the author, are responsible for performing the conversion between OS grid reference and latitude/longitude. At the time of writing (June 2007), Wikipedia's own conversion facilities are not accurate enough for buildings, as they introduce an error of about 100m (due to incorrect datum).

You may use, for example, http://www.nearby.org.uk/ to perform conversions. (Other conversion websites are available, but please check they correctly differentiate between OSGB36 and WGS84 datums.)