# Declaration part

The declaration part is used to declare the fields in several buffers.

It is also used to declare (AS/400 IBMi source) the physical and logical files to process them in reading.

### In this section

* [Field declaration](https://help.qlik.com/talend/en-US/change-data-capture-reference-guide/7.3/instructions-synoptic-field-declaration)
* [File declaration](https://help.qlik.com/talend/en-US/change-data-capture-reference-guide/7.3/file-declaration)