When you type a text in a frame, or link an article to it, by default, the first line of text touches the frame edges.
That's right if the frame has no borders or background color.
Otherwise, you may want to set an inner margin.
Important
An inner margin of frame won't be seen correctly in the WYSIWYG pane on the Articles main tab. Actually, it can cause the different text flow on the Articles main tab and on the page. Avoid to use inner margins on a text that are supposed to be edited to fit also on the Articles main tab.
To add top margin to a text, for example, of 7pt,use the tag >ta Caph+7pt< (after the >f...< tag). To add left and right margins to text use >il 7pt<>ir 7pt<. The only margin you cannot set in this way is the bottom margin.
Toggle inner margin on all selected frames
Press CTRL+SHIFT+M.
The inner margin is set from your personal preferences (Edit > Preferences > Extra > General). If you never set such preference, the default value is 6pt.
Set inner margin in the Justification palette
The value [None] or 0 makes text starting from the edge of the border of the frame. Any positive value different than 0 shifts text down and right.
Negative values shift it up and left, but if the text leaves frame completely, it disappears.