190a392d_th_PHP___Page_2___WebReference__Flags
[Filter] FILTER_VALIDATE_FLOAT [Options] decimal [Description] Checks for a floating point number or integer; returns false for any other data type. The decimal option permits the use of a comma as the decimal point. Setting the flag accepts numbers containing a thousands separator (comma is the default, but period is used when decimal is set to ','). The returned value is always stripped of the thousands separator, with a period as the decimal point. [Flags] 
FILTER_FLAG_ALLOW_THOUSAND
Data Filtering with PHP / Page 2 | WebReference
Flags