The syntax for Value Formatting is:
([prefix character/s]field[suffix character/s][{fieldoption1,fieldoption2,...}])+
where  prefix character/s and suffix character/s are optional specifiers used to control alignment and the display of positive/negative symbols; 
field can be any datatypespecific formatting or text; and 
{fieldoption(s)} is an optional qualifier, that enables additional formatting options. 
The Value Formatting definition is constructed as follows:
•The definition is composed of one or more fields. For example, the definition DD Month YYYY has three fields.
•Fields can be run together, or they can be separated by the following characters: space, hyphen, comma, colon, period, or by a text string in single or double quotes. For example, in the definition: DDMonth' in the year 'YYYY, the fields DD and Month are separated by a hyphen, and the fields Month and YYYY are separated by a text string enclosed in single quotes.
•A field can have optional prefix and/or suffix character/s. For example: <+###,##0.00.
•A field can have one or more optional fieldoptions. The fieldoption/s for each field must be contained in a single set of curly braces, and must follow the field without any intervening space. Multiple fieldoptions for a single field are separated by "," (comma). For example, in the definition: DD Month{uc,ro} YYYY, the curlybraceenclosed uc and ro are fieldoptions for the field Month.
Example of Value Formatting for an xs:decimal datatype:
"$"(##0.00)
Examples of the output would be:
$ 25.00
$ 25.42
$267.56
Example of Value Formatting for an xs:date datatype:
DD Month{uc,ro} YYYY
where  uc and ro are fieldoptions for making the Month field uppercase and readonly, respectively 
An example of the output would be:
24 SEPTEMBER 2003
A field type represents a component of the data and the way that component is to be formatted. The formatting inherent in the field type can be modified further by prefix and suffix modifiers as well as by field options. The following tables list the available field types. Note that, in the dropdown menu of the Value Formatting dialog, there are typespecific and fieldonly Value Formatting definitions. You can select one of these and modify them as required by adding prefix modifiers, suffix modifiers, and/or field options.
Field Type 
Explanation 
# 
Space if no digit at position 
0 
Zero if no digit at position 
. 
Decimal mark 
, 
Digit group separator 
Y 
Year 
y 
year (base = 1930); see Note below 
MM 
Month, must have length of 2 
DD 
Day, must have length of 2 
W 
Week number 
d 
Weekday number (1 to 7) 
i 
Day in the year (1 to 366) 
hh 
Hour (0 to 23), must have length of 2 
HH 
Hour (1 to 12), must have length of 2 
mm 
Minute, must have length of 2 
ss 
Second, must have length of 2 
AM 
AM or PM 
am 
am or pm 
AD 
AD or BC 
ad 
ad or bc 
CE 
CE or BCE 
ce 
ce or bce 
Field Type 
Explanation 
Weekday 
Weekday (Sunday, Monday...) 
WEEKDAY 
Weekday (SUNDAY, MONDAY...) 
weekday 
Weekday (sunday, monday...) 
Wkd 
Weekday (Sun, Mon...) 
WKD 
Weekday (SUN, MON...) 
wkd 
Weekday (sun, mon...) 
Month 
Month (January, February...) 
MONTH 
Month (JANUARY, FEBRUARY...) 
month 
Month (january, february...) 
Mon 
Month (Jan, Feb...) 
MON 
Month (JAN, FEB...) 
mon 
Month (jan, feb...) 
The following points relating to the length of data components should be noted:
Length of date fields: When fields such as MM, DD, HH, hh, mm, and ss are used, they must have a length of 2 in the definition. When the y or Y fields are used, the number of y or Y characters in the definition determines the length of the output. For example, if you specify YYY, then the output for a value of 2006 would be 006; for a definition of YYYYYY, it would be 002006. See also Base Year below.
Extending field length: The * (asterisk) symbol is used to extend the length of a nonsemantic numeric field (integers, decimals, etc). In the case of decimals, it can be used on either or both sides of the decimal point. For example, the Value Formatting *0.00* ensures that a number will have zeroes as specified in the formatting if these digit locations are empty, as well as any number of digits on both sides of the decimal point.
Note:  If a field does not render any text, this might be because of your region setting in Windows. For example, Windows returns an empty string for the AM/PM field if the regional language setting is German. 
Prefix and suffix modifiers are used to modify the textual alignment and positive/negative representations of fields. The following table lists the available prefix and suffix modifiers.
Prefix 
Suffix 
Explanation 
< 
Left aligned; default for text. For numbers, which are aligned right by default, this is significant if there are a fixed number of leading spaces. 

> 
Right aligned; default for numbers. 

? 
Minus symbol adjacent to number if negative; nothing otherwise. This is the default for numbers. 

<? 
Minus symbol leftaligned if negative; nothing otherwise. Number leftaligned, follows minus sign. 

<?> 
Minus symbol leftaligned if negative; nothing otherwise. Number rightaligned. 

 
 
Minus symbol adjacent to number if negative; space otherwise. Located before number (prefix), after number (suffix). 
< 
> 
Minus symbol if negative; space otherwise. Number and sign adjacent. Leftaligned (prefix); rightaligned (suffix). 
<> 
Minus symbol leftaligned if negative; space otherwise. Number rightaligned. 

+ 
+ 
Plus or minus sign always, located adjacent to number; before number (prefix), after number (suffix). 
<+ 
>+ 
Plus or minus sign always, located adjacent to number; leftaligned (prefix), rightaligned (suffix). 
<+> 
Plus or minus sign always, leftaligned; number rightaligned. 

( 
) 
Parentheses if negative; space otherwise. Adjacent to number. 
<( 
Parentheses if negative; space otherwise. Adjacent to number. Leftaligned. 

<(> 
Parentheses if negative; space otherwise. Left parentheses leftaligned; number and right parentheses adjacent and rightaligned. 

[ 
] 
Parentheses if negative; nothing otherwise. Adjacent to number. 
* 
* 
Extendable number of digits to left (prefix) or to right (suffix) 
_ 
_ 
Space 
^ 
^ 
Fill character (defined in options) 
th 
Ordinality of number in EN (st, nd, rd, or th) 

TH 
Ordinality of number in EN (ST, ND, RD, or TH) 
Field options enable advanced modifications to be made to fields. The following options are available:
Option 
Explanation 
uc 
Make uppercase 
lc 
Make lowercase 
left 
Left aligned 
right 
Right aligned 
ro 
Read (XML) only; no editing allowed 
edit 
The field is editable (active by default) 
dec=<char> 
Specify a character for the decimal point (default is point) 
sep=<char> 
Specify a character for the digit separator (default is comma) 
fill=<char> 
Specify fill character 
base=<year> 
Base year for year fields (see note below) 
pos 
Show only positive numbers; input of negative numbers allowed 
Field options should be used to generate number formatting for European languages, which interchange the commas and periods of the English language system: for example, 123.456,75.
The Value Formatting to use to obtain the formatting above would be: ###,###.##{dec=,,sep=.}
Notice that the field retains the English formatting, while it is the field options dec and sep that specify the decimal symbol and digit separator. If the decimal symbol and digit separator are not specified, these characters will default to decimal symbol and digit separator of the regional settings of the Windows OS (Control Panel  All Items  Region  Format).