Page is drawn by executing operations which are equal to small changes. These changes are stored in content stream of a page. You can display these operations by clicking Pages->Page #->Stream # in Object tree. New tab is displayed which shows pdf operators and their operands.
Stream
As mentioned above, operators control what is displayed on a page. For advanced editing, it is crucial to be able to change them. For non advanced users the operator tags are not very intuitive so a human description of each operator is shown in the status bar.
Operator description
The definition of the operators is stored in operator.hint and can be edited freely.
There many operators but only few worth changing manually. To allow fast search of these operators, operator modes were designed. After selecting one of the operator modes in Stream window, only those operators are shown. Currently there are four operator modes
operators
text operators
font operators
graphical objects iterators
Operator modes