Only in emacs22-22.2+2/src: alloc.c~
diff -ur --exclude TAGS emacs22-22.2+2/src/dispextern.h emacs22-22.2+2-tty-italic/src/dispextern.h
--- emacs22-22.2+2/src/dispextern.h	2008-01-10 12:16:14.000000000 +0000
+++ emacs22-22.2+2-tty-italic/src/dispextern.h	2009-05-24 18:01:24.000000000 +0100
@@ -1547,6 +1547,7 @@
      color of the TTY.  */
   unsigned tty_bold_p : 1;
   unsigned tty_dim_p : 1;
+  unsigned tty_italic_p : 1;
   unsigned tty_underline_p : 1;
   unsigned tty_alt_charset_p : 1;
   unsigned tty_reverse_p : 1;
@@ -2644,6 +2645,7 @@
 #define TTY_CAP_DIM		0x08
 #define TTY_CAP_BLINK		0x10
 #define TTY_CAP_ALT_CHARSET	0x20
+#define TTY_CAP_ITALIC          0x40
 
 
 /***********************************************************************
diff -ur --exclude TAGS emacs22-22.2+2/src/term.c emacs22-22.2+2-tty-italic/src/term.c
--- emacs22-22.2+2/src/term.c	2008-01-10 12:16:15.000000000 +0000
+++ emacs22-22.2+2-tty-italic/src/term.c	2009-05-24 19:00:06.000000000 +0100
@@ -320,6 +320,10 @@
 
 char *TS_enter_dim_mode;
 
+/* "ZH" -- turn on italic mode.  */
+
+char *TS_enter_italic_mode;
+
 /* "mb" -- enter blinking mode.  */
 
 char *TS_enter_blink_mode;
@@ -2034,6 +2038,9 @@
     if (MAY_USE_WITH_COLORS_P (NC_DIM))
       OUTPUT1_IF (TS_enter_dim_mode);
 
+  if (face->tty_italic_p) // italic always ok with colours, man 5 terminfo
+    OUTPUT1_IF (TS_enter_italic_mode);
+
   /* Alternate charset and blinking not yet used.  */
   if (face->tty_alt_charset_p
       && MAY_USE_WITH_COLORS_P (NC_ALT_CHARSET))
@@ -2087,6 +2094,7 @@
 	 may not turn off alt-char-mode.  */
       if (face->tty_bold_p
 	  || face->tty_dim_p
+	  || face->tty_italic_p
 	  || face->tty_reverse_p
 	  || face->tty_alt_charset_p
 	  || face->tty_blinking_p
@@ -2141,6 +2149,9 @@
   TTY_CAPABLE_P_TRY (TTY_CAP_DIM, 	TS_enter_dim_mode, 	 NC_DIM);
   TTY_CAPABLE_P_TRY (TTY_CAP_BLINK, 	TS_enter_blink_mode, 	 NC_BLINK);
   TTY_CAPABLE_P_TRY (TTY_CAP_ALT_CHARSET, TS_enter_alt_charset_mode, NC_ALT_CHARSET);
+  // italic does not collide with colours (man 5 terminfo)
+  if ( (caps & TTY_CAP_ITALIC) && !TS_enter_italic_mode )
+    return 0;
 
   /* We can do it!  */
   return 1;
@@ -2468,6 +2479,7 @@
   TS_exit_underline_mode = tgetstr ("ue", address);
   TS_enter_bold_mode = tgetstr ("md", address);
   TS_enter_dim_mode = tgetstr ("mh", address);
+  TS_enter_italic_mode = tgetstr ("ZH", address);
   TS_enter_blink_mode = tgetstr ("mb", address);
   TS_enter_reverse_mode = tgetstr ("mr", address);
   TS_enter_alt_charset_mode = tgetstr ("as", address);
diff -ur --exclude TAGS emacs22-22.2+2/src/xfaces.c emacs22-22.2+2-tty-italic/src/xfaces.c
--- emacs22-22.2+2/src/xfaces.c	2008-01-10 12:16:16.000000000 +0000
+++ emacs22-22.2+2-tty-italic/src/xfaces.c	2009-05-24 19:04:54.000000000 +0100
@@ -6020,8 +6020,7 @@
       || !UNSPECIFIEDP (attrs[LFACE_SWIDTH_INDEX])
       || !UNSPECIFIEDP (attrs[LFACE_OVERLINE_INDEX])
       || !UNSPECIFIEDP (attrs[LFACE_STRIKE_THROUGH_INDEX])
-      || !UNSPECIFIEDP (attrs[LFACE_BOX_INDEX])
-      || !UNSPECIFIEDP (attrs[LFACE_SLANT_INDEX]))
+      || !UNSPECIFIEDP (attrs[LFACE_BOX_INDEX]))
     return 0;
 
 
@@ -6072,6 +6071,16 @@
     }
 
 
+  /* italic */
+  val = attrs[LFACE_SLANT_INDEX];
+  if( !UNSPECIFIEDP (val) )
+    {
+      if (face_attr_equal_p (val, def_attrs[LFACE_SLANT_INDEX]))
+        return 0;		/* same as default */
+      else
+        test_caps |= TTY_CAP_ITALIC;
+    }
+
   /* Color testing.  */
 
   /* Default the color indices in FG_TTY_COLOR and BG_TTY_COLOR, since
@@ -7508,7 +7517,7 @@
   if (weight > XLFD_WEIGHT_MEDIUM)
     face->tty_bold_p = 1;
   if (weight < XLFD_WEIGHT_MEDIUM || slant != XLFD_SLANT_ROMAN)
-    face->tty_dim_p = 1;
+    face->tty_italic_p = 1;
   if (!NILP (attrs[LFACE_UNDERLINE_INDEX]))
     face->tty_underline_p = 1;
   if (!NILP (attrs[LFACE_INVERSE_INDEX]))