Whenever an application exchanges data using the DDE protocol, it must specify the format of the data in the usFormat field of the DDESTRUCT data structure. The system-defined standard format for exchanging text data is DDEFMT_TEXT. Applications can also use constant names to specify the format of data to be exchanged listed in the following table:
旼컴컴컴컴컴컴컴컴컴컴컫컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿏ata Format Name 쿏escription � 쳐컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿞ZFMT_BITMAP 쿞pecifies that the data is a bit map. � 쳐컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿞ZFMT_CPTEXT 쿞pecifies text whose format is defined� � 쿫y a CPTEXT data structure. � � 쿌pplications can use this format to � � 쿾ass multiple-language strings without� � 쿬hanging the conversation context. � 쳐컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿞ZFMT_DIF 쿞pecifies that the data is in Data � � 쿔mage Format (DIF). � 쳐컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿞ZFMT_DSPBITMAP 쿞pecifies that the data is a bit-map � � 퀁epresentation of a private data � � 쿯ormat. � 쳐컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿞ZFMT_DSPMETAFILE 쿞pecifies that the data is a metafile � � 퀁epresentation of a private data � � 쿯ormat. � 쳐컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿞ZFMT_DSPMETAFILEPICT 쿞pecifies that the data is a metafile � � 쿾icture representation of a private � � 쿭ata format. � 쳐컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿞ZFMT_DSPTEXT 쿞pecifies that the data is a text � � 퀁epresentation of a private data � � 쿯ormat. � 쳐컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿞ZFMT_LINK 쿞pecifies that the data is in � � 쿹ink-file format. � 쳐컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿞ZFMT_METAFILE 쿞pecifies that the data is a metafile.� 쳐컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿞ZFMT_METAFILEPICT 쿞pecifies that the data is a metafile � � 쿾icture defined by an MFP data � � 퀂tructure. � 쳐컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿞ZFMT_OEMTEXT 쿞pecifies that the data is in OEM Text� � 쿯ormat. � 쳐컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿞ZFMT_PALETTE 쿞pecifies that the data is in palette � � 쿯ormat. � 쳐컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿞ZFMT_SYLK 쿞pecifies that the data is in � � 쿞ynchronous Link format. � 쳐컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿞ZFMT_TEXT 쿞pecifies that the data is an array of� � 퀃ext characters. These characters can � � 쿶nclude new-line characters to � � 쿶ndicate linebreaks. The zero-length � � 쿬haracter indicates the end of the � � 퀃ext data. � 쳐컴컴컴컴컴컴컴컴컴컴컵컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� 쿞ZFMT_TIFF 쿞pecifies that the data is in Tag � � 쿔mage File Format (TIFF). � 읕컴컴컴컴컴컴컴컴컴컴컨컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴�
Applications can define their own data formats. However, each nonstandard DDE format must have a unique identification number. To receive an identification number for a nonstardard format, the application must register the name of the format in the system atom table. Other applications that have the name of the format can then query the system atom table for the format's identification number. This method ensures that all applications use the same atom to identify a format.