# Coldef
> [HTML Version](coldef.htm)
This input parameter, "column definition", defines the column configuration layout and other related details of the tree configuration, according to one of three syntax variations:
• [Traditional Coldef Syntax](traditionalcoldefsyntax.htm.md)
• [Simple Multi-Column Coldef Syntax](simplemulti-columncoldef.htm.md)
• Advanced Coldef syntax
**Advanced Coldef Syntax**
To use the Advanced _coldef _syntax, you must specify the XTF\_COLDFX option in _flags_, and then provide a _coldef_ string in the following syntax:
**cpos~ cwidth~ ctitle~ cformat \{~option1 = value1\{ ~option2 = value2...\} ~~cpos~ cwidth...~~**
This syntax specification consists of a series of column definitions, one per column, delimited by a pair of tildes (~~). Each column definition begins with four mandatory parameters (_cpos_, c_width_, c_title_ and c_format_), each delimited by a single tilde, followed by zero or more optional [Advanced Coldef Options](advancedcoldefoptions.htm.md) using the form (_optionN_=_valueN_). This is admittedly cryptic, but has the virtues of being flexible, easily extensible, compact, and easy to map.
| | |
|------|------|
| **Parameter** | **Description** |
| [Cpos, Cwidth](cposcwidth.htm.md) | Define the starting position and width of the column. |
| [Ctitle](ctitle.htm.md) | Sets column title (header), and optionally, footer text. |
| [Cformat](cformat.htm.md) | Specifies formatting and sorting of column contents. |
| | [Advanced Coldef Options](advancedcoldefoptions.htm.md). |
**See Also**
• [File Mode Coldef Extensions](filemodecoldefextensions.htm.md)
• [Advanced Syntax Example](advancedsyntaxexample.htm.md) for tips on specifying column attributes as well as widths
• [.OFFSIZ\$](offsiz$().htm.md) to simplify determination of _cpos_ and _cwidth_ for structure members