Certain reserved attributes have special meanings that are understood by the generic FrontPage Component Properties dialog. These reserved attributes are not required, but if present must be used as described below. Other attributes have a leading character and a dash in their name to indicate their data type. This information is used by the generic FrontPage Component Properties dialog to display type-appropriate controls for modifying the attribute value.
The following table summarizes the reserved BTL attributes and what they mean:
| Attribute | Meaning |
| NAME | A short user-readable name for the component type. Often just the shortname with spaces, that is |
| TAG | The HTML tag type returned by the Evaluate method of the component. The value should be a valid HTML tag (with no < or >; example: |
| PREVIEW | A preview string, possibly containing some HTML tags. If present, FrontPage uses this as the edit-time representation of the component. If it is missing (and the component is unknown), FrontPage displays the component name within a pair of square brackets, like this: If a TAG is provided, then the PREVIEW string must match the tag type. For example, if TAG=H2, then a valid PREVIEW string would be something like “<H2>Test Component</H2>”. The PREVIEW string must have any embedded <, &, >, and “ characters properly escaped. The previous example would be stored in BTL file as: |
| DESCR | A short (one or two sentences at most) description of what the component is and does. This is displayed by the generic FrontPage Component Properties dialog. Extra white space and new lines are removed from the description string before it is show to the user. |
| HELP | A slightly longer (a paragraph or two at most) description that is displayed when the user clicks the Help button in the generic FrontPage Component Properties dialog. Extra white space and new lines are removed from the help string before it is shown to the user. To force a new line, put \n in the string. Use \\ for a single back-slash. |