diff --git a/man2/s390_sthyi.2 b/man2/s390_sthyi.2
index 4b36758f3..026a56a1a 100644
--- a/man2/s390_sthyi.2
+++ b/man2/s390_sthyi.2
@@ -44,23 +44,34 @@ The
 .I function_code
 argument indicates which function to perform.
 The following code(s) are supported:
-.RB ( 0 )
+.TP
+0
 Return CP (Central Processor) and IFL (Integrated Facility for Linux)
 capacity information.
 .PP
 The
 .I buffer 
-argument specifies the address of response buffer. If the system
+argument specifies the address of a response buffer. If the system
 call returns 0, the response buffer will be filled with CPU capacity
 information. Otherwise, the response buffer's content is unchanged.
 .PP
 The
 .I return_code
-argument stores the return code of the STHYI instruction, success
-.RB ( 0 )
-or unsupported function code
-.RB ( 4 ).
-For details about return code, function_code, and buffer argument,
++argument stores the return code of the STHYI instruction, using one
+of the
+following values:
+.TP 8
+.B 0
+Success.
+.TP
+.B 4
+Unsupported function code.
+.PP
+For further details about
+.IR return_code ,
+.IR function_code ,
+and
+.IR buffer ,
 please see section
 .IR "CONFORMING TO"
 below.
@@ -75,7 +86,7 @@ On success, the return value of
 matches the condition code of the STHYI instructions, which is a value
 between 0-3 (that is: emulation succeeded).
 Return value of 0 indicates that CPU capacity information is stored to
-.I buffer.
+.IR buffer .
 Return value of 3 indicates "unsupported function code" and buffer's
 content is unchanged.
 Return value of 1 and 2 are reserved.