Tags and markings are not retained from one session to the next, if the data table's key columns do not uniquely identify all of its rows.
Key columns are used to uniquely identify all rows in a data table. You need to specify key columns if you want to be able to see the markings that were active when saving the file, or if you want any specified tags or bookmarks to be reapplied when reopening the analysis file.
Even after these key columns have been defined,
if the data table's key columns do not uniquely identify all of its rows, or if any key column contains a NULL value, then tags and markings will not be retained from one session to the next.
Key columns are specified under "Data Table Properties > General tab":
Sometimes you need to specify more than one key column, to uniquely identify rows. These key columns should not contain any NULL values.
If any key column has a NULL value, even when the resulting Combination Column appears to uniquely define all rows, Spotfire will still be unable to keep that Tag or Marking beyond the end of the current session. This is because a NULL value represents an unknown that cannot be used to test for uniqueness.