diff --git a/README.md b/README.md
index 4a06da6..27364aa 100644
--- a/README.md
+++ b/README.md
@@ -12,10 +12,28 @@ git clone https://git.bodiccea.tk/bruno/Le-Compte-est-Bon.git
 
 ## Build
 
-To display mode debug information, you may first enable some DEBUG flags in the `Makefile`.
+To display more debug information, you may first enable some DEBUG flags in the `Makefile`. I usually use the `-DDEBUG`, `-DDEBUG_MAIN`, and `-DDEBUG_MEM`, as below
+
+```makefile
+CFLAGS:=$(CFLAGS) -DDEBUG              #     general (signal handler, etc...)
+CFLAGS:=$(CFLAGS) -DDEBUG_MAIN         #     general information in main
+#CFLAGS:=$(CFLAGS) -DDEBUG_MAINSLEEP    #     sleep 1 sec within main loop (SIGINTR test)
+#CFLAGS:=$(CFLAGS) -DDEBUG_MAINLOOP     #     main loop (do not use this!)
+#CFLAGS:=$(CFLAGS) -DDEBUG_TIMER        #     timer
+#CFLAGS:=$(CFLAGS) -DDEBUG_SIGNAL       #     signal
+#CFLAGS:=$(CFLAGS) -DDEBUG_BEST         #     best control
+#CFLAGS:=$(CFLAGS) -DDEBUG_TREE         #     tree
+#CFLAGS:=$(CFLAGS) -DDEBUG_OPER         #     oper
+#CFLAGS:=$(CFLAGS) -DDEBUG_STACK        #     stack
+#CFLAGS:=$(CFLAGS) -DDEBUG_STACK2       #     stack - more details
+#CFLAGS:=$(CFLAGS) -DDEBUG_EVAL         #     eval
+#CFLAGS:=$(CFLAGS) -DDEBUG_EVAL2        #     eval 2
+#CFLAGS:=$(CFLAGS) -DDEBUG_EVAL3        #     eval 3
+CFLAGS:=$(CFLAGS) -DDEBUG_MEM          #     malloc
+```
 
 To build the binaries just run:
-``` shellsession
+```console
 $ make lceb
 ```
 
@@ -37,7 +55,7 @@ trees           :             14
 max evaluations :        537,600
 Le compte est bon: 5 solutions with 2 ops (1st after 0.00030 secs).
 1 8 7 - +
-1 8 8 / +
+1 8 8 / +g
 1 7 7 / +
 1 8 + 7 -
 8 7 1 - -