Um, "read-only" means that you aren't allowed to edit the file, or save
changes to that file without making a copy.
A text file is a file that is "plain text" and contains no formatting
features such as those found in a "word processor" document.
A "text" file can be set "read only" so perhaps you are thinking of RTF
file type which is "revisable text format" which is a "word processor"
document.
