https://community.appian.com/discussions/f/general/14147/illegal-not-allowed-characters-in-rt-identifiersHi Guys, we have a legacy table whose primary key (column X) is getting generated by a dynamic string(alpha-numeric n special characters) of six characters. The DSE had been used in entity Back record . if the # is available in X column value , uponen-USTelligent Community 12https://community.appian.com/thread/64011?ContentTypeID=1Mon, 14 Jan 2019 14:03:39 GMTd3a83456-d57b-489c-a84c-4e8267bb592a:be15330a-a8ce-4159-9bc1-1cd246e4a492Vinay Kumar RaiHi,<br /> <br /> As per the best practice of Database or Appian, the identifier/Primary Key should always be number not string.<br /> <br /> Thanks<div style="clear:both;"></div>