--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/host-name.rst	Mon Feb 22 12:46:36 2016 +0200
@@ -0,0 +1,33 @@
+.. -*- coding: utf-8; -*-
+.. include:: HEADER.rst
+
+============
+ Host names
+============
+.. contents::
+   :local:
+
+What characters may be used for host name?
+==========================================
+
+As say RFC 952 hostname is a text string up to 24 characters drawn from the alphabet
+(A-Z), digits (0-9), minus sign (-), and period (.).
+
+As say RFC 1035::
+
+  <domain> ::= <subdomain> | " "
+
+  <subdomain> ::= <label> | <subdomain> "." <label>
+
+  <label> ::= <letter> [ [ <ldh-str> ] <let-dig> ]
+
+  <ldh-str> ::= <let-dig-hyp> | <let-dig-hyp> <ldh-str>
+
+  <let-dig-hyp> ::= <let-dig> | "-"
+
+  <let-dig> ::= <letter> | <digit>
+
+  <letter> ::= any one of the 52 alphabetic characters A through Z in
+  upper case and a through z in lower case
+
+  <digit> ::= any one of the ten digits 0 through 9