Clarified that AAIP is only allowed if RRIP is present

doc/susp_aaip_0_2.txt

@@ -37,12 +37,15 @@ System Entries Provided by this Specification
 
 Description of the "AA" System Use Entry
 
+This SUSP field and the ER entry of AAIP shall only be present if the ER entry
+of RRIP is present.
+
 The field has exactly the same layout as RRIP field SL. One has to expect
 more data bytes than with SL, though, and any of the 256 possible byte values. 
 The reader shall be prepared to detect and handle oversized data.
 
 One or more AA fields form the Attribute List of a file object with
-a pare number of components. Each two consequtive components form a pair of
+an even number of components. Each two consequtive components form a pair of
 Name and Value. The empty name is reserved for a compact representation of
 ALCs. The meaning of any other name is not specified by this document.
 
@@ -275,6 +278,8 @@ Example: User id number 1001 gets associated with user name "lisa"
 
 Specification of the ER System Use Entry Values for AAIP:
 
+This ER system entry shall only be present if the ER entry of RRIP is present.
+
 The Extension Version number for this version of AAIP shall be 1.
 
 The Extension Identifier field shall be "AAIP_0002" with Identifier Length 9.