Case-sensitive file and folder names
When working in a DITA environment, files and folders must be treated as case-sensitive, and all members of the team must adhere to agreed file naming conventions.
Even though some tools and environments may be case-insensitive when it comes to file and folder names, you must be totally consistent with the case of your file and folder names. One important aspect of DITA is interchangeability, and if you are not consistent with file name case, your documents may cause problems when you interchange with someone in a case-sensitive environment.
Further, some DITA tools treat file names differently within the same workflow (or pipeline). For example, one part of the DITA Open Toolkit pipeline checks with the operating system to see if a file (abc.dita) exists before proceeding to the next step. The operating system may respond yes if a file named ABC.dita exists, even though a file name of the exact case (abc.dita) does not exist. When the next step (which is case aware) commences, it may crash because it cannot find a file abc.dita.
Treat file and folder names as case-sensitive.