I used "svn st" to an svn root which has external file and directory. Every times file and directory 's status "X" has diff location.is it a rule?,I can't find in doc.
svn status
output is formatted in columns.
When you use svn help status
you can have a look what these columns are and what the contents mean.
For your X
it is:
First column: Says if item was added, deleted, or otherwise changed 'X' an unversioned directory created by an externals definition
Fifth column: Whether the item is switched or a file external 'X' a versioned file created by an eXternals definition
Be aware, that the documentation on svn status for some reason does not contain the information about the fifth column.