Both headline-style capitalization and sentence-style are used, depending on the item. For the most part, these guidelines also agree with the IBM Web Interface Style Guidelines, so that if you are designing for both the Web and rich client, consider using the same properties file.
Use headline-style capitalization for the following:
- Menus and menu items
- Command buttons (push buttons)
- Titles, including:
- Title bars, window titles
- Dialog title bars
Headline-style capitalization means capitalize the first letter of each word, except for:
- Articles such as “a”, “an”, and “the”
- Short prepositions (5 or fewer letters) such as “for”, “in”, “of”, “on”, “to”, when these prepositions are between two words. (For example, in the case of Save As… and Save as Draft…. “as” is capitalized in the first instance because it is the last word.)
- Do not include ending punctuation.
Use sentence-style capitalization for all labels in a window or dialog, including labels for the following:
- Check boxes
- Radio buttons
- Group box (or group bar) titles
- Simple text fields
Sentence-style capitalization means capitalize the first letter of the first word and any proper nouns such as “Lotus”. Refer to Error! Reference source not found.
for good examples of sentence-style capitalization in field labels.
Put a colon at the end of labels for controls in a form or dialog, as shown in figure 1. Terminate full sentences (such as those in error messages) with the appropriate punctuation, such as a period, exclamation point or question mark, except for full sentences used in check boxes and radio buttons.
Figure 1. Use colons after labels
You must provide tooltips for visual elements that have no text labels. You do not need to create tooltips for visual elements with text labels. Do not use terminating punctuation for tooltips.
For menu and action bar items, use ellipses (three periods at the end of the text) when the item launches a dialog that requires user input (just clicking an OK button does not count). Do not use ellipses when the item brings up a new Tab.