To convert a selected text block into a hidden comment

On the Type menu, point to Character, and then click Blind text.

To revert text to printable

Select it in the source pane and then repeat the above.

To change font and color of hidden text

1.On the Edit menu, click Preferences, and then on the Source tab, click Colors tab.

2.In the Notes mode section, click Add if the list is empty, and then select attributes (foreground color, background, strike out, underline) for the notes mode level 1 (standard hidden text).

3.To edit, or delete a color, select a notes mode entry and then click Edit, or Delete.

4.Repeat steps to set attributes for other levels of the hidden text, e.g. level 2, and so on.