The command line interface is broken into two segments. Spell checking and saving.
spellcheck [date_from] [date_to] checks photos whose data taken are between date_from and date_to. This is different from flickr’s tracking of the date uploaded.
If date_to is left blank, then it checks everything to the present. If date_from is left blank, then it checks everything from 40 days ago to the present.
Dates are expected to be in the MM/DD/YYYY format
spellchecktags gets the full list of tags and then outputs the list of corrections to the screen. Due to the way the Flickr API works, you will need to manually go to Flickr and change the tags through their web interface.
savechanges takes all the spelling changes from spellcheck and commits them to Flickr.
showchanges shows all the spelling changes that would be saved to Flickr from a savechanges