# Once the Admin mode is enabled you can add a new file extension by creating a new row and setting a description, name and value<br/>[[File:UI_HowTo_Add_a_file_extension_06.png|880 px|border|alt=Create a new Selective Item for a new file extension|Create a new Selective Item for a new file extension]]<!--
-->{{Attention|The value of the new item must include the extension in the format *.wmv!}}
# Assign your Now you have to related the new file extension item to the Selective List for list of known file types<br/> Open : first, browse to the SELECTIVELIST MetaClass [[SELECTIVELIST]] within the ''{System.List}'' namespace and connect the objects called FILETYPES list named ''FILETYPE'' with the {{Relation_EditorRelation Editor}} to add your . Second, relate the new file extension via drag & dropSelecive Item to this list.<br/>[[File:UI_HowTo_Add_a_file_extension_07.png|220 px|border|alt=Add a file extension|Add a file extension]]<br/>[[File:UI_HowTo_Add_a_file_extension_08.png|220 px|border|alt=Add a file extension|Add a file extension]]<br/>[[File:UI_HowTo_Add_a_file_extension_09.png|220 px|border|alt=Add a file extension|Add a file extension]]<br/>{{Attention|Please do not forget the save button.}}
# [[HowTo:Release_MetaDefinitions|Release the new MetaDefintiions]]