Adobe InDesign - Manual (Page 26)

Primary text frame indicator
To designate a primary text frame, open a master page and do one of the following:
Click the symbol near the left-upper corner of the text frame
Right-click on text frame and choose Primary Text Frame
Note: Only a single text frame can be designated as primary on a master page.
Text frame fitting options
Flexible width columns
You can use the Flexible width option to adjust the number and width of columns as the text frame is resized. Columns are automatically added or
deleted when the maximum column width is reached as the text frame is resized.
Choose Flexible Width from the Columns drop down list in the Text Frame Options dialog box (Object > Text Frame Options)
Persistent text frame fitting options
Auto-size text frame options make it possible to set up a text frame so that it is automatically resized when you add, delete, or edit text.
To access the Auto-size options, do the following:
1. Select a text frame and choose Object > Text Frame Options
2. Click Auto-size.
Auto Size options
Packaging and preflight
21