NAVLIPI uses the 26 letters (glyphs) of the Latin (Roman) alphabet, specifically as used for English, i.e. without diacritic marks, accent marks, etc., or transformed letters, e.g. as found in versions of the Latin alphabet used in many other languages, such Czech (e.g. č, š) or even French (e.g. ç), plus just fifteen (15) additional letters.
Three of these additional letters are borrowed from Greek (ε; Ω; η). Eleven of them are transformed: ᴐ (an inverted c); ƪ (an inverted j); ȓ ; t ; d ; ր; o/; o//; z; ƹ (transformed g); and 2 (the number 2, but used as a letter)). This use in NAVLIPI is thus actually not unlike transformed Latin letters used in such languages as Czech (e.g. č, ž, á, í ) or even French (e.g. é, ç). And only one letter is entirely new (ⱡ). As noted elsewhere in this document, the Latin script was chosen as basis because it is today (2020), fortunately or unfortunately, the most recognized script worldwide. And in the Indian Subcontinent political context, the Latin script carries less “baggage”, than, say, the Dewanaagari or Tamil or Arabic scripts.
The 15 additional NAVLIPI letters, and their use, are listed in summary below. Only lower case letters are listed, except in the last case, since the upper case letters are obvious extensions of the lower case ones: