Updated FAQ (coding style) (markdown)

FAQ-(coding-style).md

@@ -2,9 +2,16 @@
 
 ## Why don't you add ```_t``` suffix to typedef-ed symbols?
 
-```_t``` suffix is reserved by POSIX.
+There are some reasons.
+
+* ```_t``` suffix is reserved by POSIX.
 Even though We don't express to support POSIX, we can't ignore it.
 
+* We have already defined some types with no ```_t``` suffix like mrb_int.
+We want to keep naming consistency.
+
+* Matz don't like ```_t``` suffix. :-p
+
 ## I found a symbol without ```mrb_```/```MRB_``` prefix in the header file.
 
 I'm sorry. It is ill formed. Please report to issue tracking or send pull request.
@@ -17,4 +24,4 @@ Please define them by yourself.
 
 Definitions depends on your target architecture and your compiler implementation.
 So it's difficult to give you general guidelines.
-Please consult the compiler vendor.
+Please consult the compiler vendor.