forms - Should label and field be separated with colon?

When you have a form with fields and captions for these fields, should you do it like that:

Field1: [                       ]
Field2: [                       ]

or like that:

Field1  [                       ]
Field2  [                       ]

I saw both used in popular application. Microsoft generally uses colons (My computer properties -> Computer Name tab is one example). Opera browser doesn't use colons as separators on forms (example: Preferences form).

I personally don't have a strong opinion on which one is better. But I'm working on this "1000s of winforms" app where I suspect we have forms with and without colons so I would really like to set a standard and go one way or another on all forms because the inconsistency is far worse than any of the options.

Answer

If your field and captions have different visual styles then the colon won't be necessary. The colon is used in text to separate parts of text since pure (non-formatted) text visually can't be separated.

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Colon required:

Field1: This is caption 1

Field2: This is another caption

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Colon not required:

Field1 This is caption 1
Field2 This is another caption