diff -r 00f9a66da2eb -r cf21d062a601 data/dictionary.xml
--- a/data/dictionary.xml	Thu Jul 11 18:31:52 2013 +0200
+++ b/data/dictionary.xml	Thu Jul 11 18:47:13 2013 +0200
@@ -43,7 +43,24 @@
 	</concept>
 	<concept>
 		<term abbreviation="SMS" completeForm="short message service" language="en"/>
-		<explanation language="en"><text></text></explanation>
+		<explanation language="en">
+			<text>
+				a service or particular short text message sent from or to a mobile phone;
+				length of the content in one message is 140 bytes (octets), the number of characters depends on encoding, if 7-bit one is used, it is well known 160 characters;
+				the number „160“ is iconic for SMS
+			</text>
+		</explanation>
+	</concept>
+	<concept>
+		<term abbreviation="" completeForm="octet" language="en"/>
+		<term abbreviation="" completeForm="byte" language="en"/>
+		<explanation language="en">
+			<text>
+				a unit of digital information;
+				byte (almost always) consists of 8 bits, which means 256 possible values (2^8);
+				octet is a synonym for 8-bit byte which accents that we really mean the 8-bit byte (and not e.g. the 7-bit one)
+			</text>
+		</explanation>
 	</concept>
 	<concept>
 		<term abbreviation="MMS" completeForm="multimedia messaging service" language="en"/>