The platform dependent length modifier for conversion specifiers for scanning and printing values of type gint16 or guint16 It is a string literal, but doesn't include the percent-sign, such that you can add precision and length modifiers between percent-sign and conversion specifier and append a conversion specifier.

The following example prints "0x7b";

gint16 value = 123;
g_print ("%#" G_GINT16_MODIFIER "x", value);
enum GINT16_MODIFIER = "h";