I'm trying to get a tab space equivalent to a punctuation space but I just can't seem to find my way around the problem. I intend to use my tab space between three letter abbreviations and phone numbers (phone book format, line-by-line items).
I'm not sure if this answers your question..... but it seems relevant.
I would not use a tab for such an item. InDesign has white space characters specifically to fill the need you describe.
As for tabs specifically. I believe you can set them as close together as the glyphs will allow and there is no "minimum" distance.
Thing is if they tabs are 5pts apart and a glyph need 7pts to display.. then tabs won't be honored. You have to set the tabs specifically far enough apart so that all glyphs have room to display.
Depending upon the layout, a table with 1 cell per glyph may also work well.
What you really need to look into are monospaced fonts.
- A good monospace, condensed and open-source typeface?
- What font types are good for a technical document?
- Which fonts have the same width for every character?