The Spell Check dialog box also shows in a separate edit box the words immediately surrounding the suspected misspelled word. This is to provide the user with the context. The user can click on a Continue button or an Ignore All button. If the user has not changed the displayed word, the Continue button just lets the spell checker go on. If the word was modified by the user, clicking Continue causes the new spelling to replace the old.
All button tells the spell checker to ignore all instances of the current word.
They would like you to register , but that does not seem to be necessary in order to read the tutorial. The tutorial has 6 major sections. It is suggested that you at least read the first three as this will help you to understand what we are getting into. If you have an extra hour or two, you might want to read all six sections and do the practice exercises that they outline. Although the title says that the tutorial is for Version 6.x, it works fine under 5.0.