For the English, German, Ganassi, and Renaissance fingerings I have included all the fingerings known to me. Here also the first fingering is the standard. It can be used basically on every recorder. Only in the case where the produced tone is not stable or not in tune should you try an alternate fingering. Experiment and use a tuning device to find the best fingering for your recorder.
These alternate fingerings are also needed in specific situations. For example, a fast sequence of notes where the standard fingering is not applicable because it is to slow.
Some fingerings in my charts show a comment. This can help you to find out for what purpose this fingering is good for. If your tone is to sharp look for a fingering with the comment "flat" or "forte" and if it is flat, look for "sharp" or "piano". The charts for Piano-Forte-Fingerings are therefore another source for alternate fingerings.