--- a/th_string.h	Wed May 10 21:01:27 2017 +0300
+++ b/th_string.h	Sun May 14 13:13:30 2017 +0300
@@ -5,6 +5,8 @@
  *
  * Please read file 'COPYING' for information on license and distribution.
  */
+/// @file
+/// @brief String utility functions
 #ifndef TH_STRING_H
 #define TH_STRING_H
 
@@ -17,7 +19,7 @@
 extern "C" {
 #endif
 
-/* Macros
+/** @def String utility wrapper macros
  */
 #define th_isalnum(c)   isalnum((int)(unsigned char) c)
 #define th_isalpha(c)   isalpha((int)(unsigned char) c)
@@ -40,6 +42,8 @@
 #define th_toupper(c)   toupper((int)(unsigned char) c)
 
 
+/** @def String trimming option flags for th_strdup_trim()
+ */
 enum
 {
     TH_TRIM_START    = 1,
@@ -48,6 +52,8 @@
 };
 
 
+/** @def Internal *printf() implementation flags
+ */
 enum
 {
     TH_PF_NONE       = 0x0000,
@@ -66,15 +72,19 @@
 };
 
 
+/** @def Internal *printf() context structure
+ */
 typedef struct
 {
-    char *buf;
-    size_t size, pos;
-    int ipos;
-    void *data;
+    char *buf;           ///< Resulting string buffer pointer (may not be used if printing to file or so)
+    size_t size, pos;    ///< Size of result string buffer, and current position in it
+    int ipos;            ///< Signed position
+    void *data;          ///< Other data (for example FILE pointer)
 } th_vprintf_ctx;
 
 
+/** @def putch() helper function typedef for pnternal printf() implementation
+ */
 typedef int (*th_vprintf_putch)(th_vprintf_ctx *ctx, const char ch);