# LDF-Related Codes

_Type_ **u** (LDF-Controlled Format) and **||u** (ignore LDF) have varying effects on dates, times, Y/N and numeric fields whose format options may vary based on the Language Definition File (LDF). Note that unlike most _type_ codes which act independent of the order they appear in, **u** and **||u** must generally precede the associated _type_ codes.

For date fields (**D**, **d**, and **U**), **u** has no effect. The **D** and **d** date fields use the LDF format by default, and the European date (**U**) fields always use the European format. The only LDF-related option here is to precede the **D** or **d** with **||u** to force the American format even when the LDF specifies European format. (That could be a useful workaround for running a USA-developed app, which assumed American date format, in some other part of the world.) Note that a good strategy for avoiding confusion within an application related to differing date formats is to always add the **>** code to force \{CC\}YYMMDD format internally, regardless of the display and edit format. Also note that in a GUI environment where a date-specific control (such as a calendar control) is being used, the edit/display format will generally be determined by the regional settings of the client PC (making the **>** option even more important.)

For Y/N fields, the affirmative and negative characters are determined by the LDF, unless you precede the _type_ **Y** or **YN** with **||u**, in which case it will use "Y" and no "N". In the GUI environment, you may want to use _type_ **||c** to convert your Y/N fields to checkboxes (which avoids all language and regional confusion).

For numeric fields (**#**, **H**, **\$**), **u** forces INFLD to use the decimal point and thousands separator characters specified in the LDF, rather than the USA default characters ("." and "," respectively). In this case, the **u** does not have to precede the numeric _type_ code.

Note that this will only have an effect if the field would otherwise allow entry or display of decimals and thousands separators. See _[type](http://www.microsabio.net/dist/60rel/doc/conref/type.htm)_ codes ** . **,** M**, **\$**, **H** as well as the [defpt](defpt.md) and [maxpt](maxpt.md) parameters.

**See Also**

The system parameter [LANGUAGE](language.md) for establishing the LDF, and [GTLANG](gtlangsbr.md) for how to query it.