I have tried to faithfully duplicate de Rippe's original fingering notations, without attempting to correct them.

He uses only four types of fingering notations:

1. A slash, indicating a note or chord that is held while playing other notes.   This is rarely used when the note to be held is an open string, so it can really be used as an indicator that a note or notes are to be held by the left hand while playing others. The typeset used only has one kind of slash, contained between two lines and extending only the length of about two and a half notes.  Sometimes, two slashes are combined end to end to form a longer one.  Since these are of fixed length, they can reflect only approximately the actual duration of the held notes.  In my transcription, I have tried to extend these slashes as needed to show the actual duration of the hold.  Obviously, this is a judgment call  Overall, I am mindful of what Dowland said on this topic:  hold notes as long as possible, unless or until it sounds bad.
2. Dots to the right of the notes in a chord (when there are two or more notes).  This does not necessarily indicate that these notes should be all played by an upward raking of the index finger, as in early 17th century Airs de Cour, for example.  Indeed, in many cases these dotted notes are not adjacent and could not be played in this way.  I interpret these dots to indicate that the notes are to be played by something other than the thumb.  Some would require three right-hand fingers to be executed.
3. A dot underneath a chord (of two or more notes).  This appears to be interchangeable with (2), above.
4. A dot under a single note.  This means a note to be played not by the thumb -- usually, but not always, by the index finger.

Dots (2), (3, and (4), above often indicate a weak beat, but they often appear on strong beats when they constitute a more efficient way to play the notes than would a strict alternation between thumb and fingers.  Dots rarely appear on the 5th course, and more rarely on the 6th, which would indicate that passages played on the lower courses are usually played by the thumb alone.  On the other hand, on the upper courses, we often see two or more contiguous dotted notes, indicating, perhaps, an alternation of index and middle fingers on weak and strong beats, where practicable.

These notations are used somewhat inconsistently and should be regarded as reminders rather than being considered canonical.

Adrian Le Roy uses similar notations in a similar way, incidentally.

--Sarge Gerbode