Axapta uses quite a number of file extensions for the files that are installed as part of Axapta. Even though at first sight, people will be bewildered with these te(o)ns acronyms/extensions, it follows a very good naming convention and once it’s understood, it is very easy to follow these file names and extensions. First Letter: owner of file: A Application K Kernel Second Letter: contents of file: L Label O Object (as is AOT) T Text (only TKD) D Developer Documentation H Online Help Third Letter: Type of file. D Data I Index C Cache T Temporary So a file with extension .ald is ApplicationLabelData file. Thanks to Michael Fruergaard Pontoppidan (who came out this table) and Tao Wang (who provided this info to me)