-Simultaneous editing if not detected can cause one user to lose his
-work. Emacs detects all cases of simultaneous editing and warns one of
-the users to investigate. @xref{Interlocking,,Simultaneous Editing}.
+Simultaneous editing, if not detected, can cause one user to lose his
+or her work. Emacs detects all cases of simultaneous editing, and
+warns one of the users to investigate.
+@xref{Interlocking,Interlocking,Simultaneous Editing}.
+
+@item @key{SPC}
+@key{SPC} is the space character, which you enter by pressing the
+space bar.
+
+@item Speedbar
+The speedbar is a special tall frame that provides fast access to Emacs
+buffers, functions within those buffers, Info nodes, and other
+interesting parts of text within Emacs. @xref{Speedbar}.
+
+@item Spell Checking
+Spell checking means checking correctness of the written form of each
+one of the words in a text. Emacs uses the Ispell spelling-checker
+program to check the spelling of parts of a buffer via a convenient user
+interface. @xref{Spelling}.