linking templates

When you start a new part a template is used. A template can be created by opening the default start part, customizing all the document properties, renaming planes, setting up views, material properties, etc. Then save the template using:

FILE/SAVEAS/.slddot or for assemblies FILE/SAVEAS/.sldasm

You can do similar for a drawing but there are far more things you can setup like sheet formats, predefined views, etc.

Also, don't forget that you can preassign customproperties in a template. Two that come to mind that are almost universal are material and weight/mass.

What I have not described is not technically linking because once the part has been started it is not possible to change the template and have the part change as for example a linked spreadsheet in a drawing document would behave.

It is possible to change the template manually by going to the sheet properties dialogue and browsing for a template. This would then mean that the template updated with any changes.

In a drawing document that is true. In a part document which is what the subject of camtd's question was there are no sheet formats.