Updates to User Guide.

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@8049 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

doc/user_guide/en/decoder_notes.adoc

@@ -9,33 +9,25 @@ When an operator decides to answer a CQ, he already knows his own
 callsign and that of his potential QSO partner.  He therefore knows
 what to expect for at least 56 of the 72 message bits in a
 standard-format response to his call.  The _WSJT-X_ decoders for QRA64
-and FT8 can use these AP bits to decode messages containing them with
-higher sensitivity than otherwise possible.
+and FT8 can use these and similar AP bits to decode messages
+containing them with higher sensitivity than otherwise possible.
 
 We have implemented AP decoding in slightly different ways in QRA64
 and FT8.  To provide some explicit examples for users, we provide here
 a brief description of the FT8 behavior.
 
-The FT8 decoder always tries first to decode a signal without using
-any AP information. If this attempt fails, and if *Enable AP* is
-checked on the *Decode* menu, a second attempt hypothesizes that the
-message contains callsigns MyCall and DxCall. If the QSO has
-progressed to the point where signal reports have been exchanged, a
-third attempt hypothesizes that the message contains the known
-callsigns followed by RRR, RR73, or 73.
-
 AP decoding attempts effectively set the AP bits to the hypothesized
-values, as if they had been received perfectly.  The decoder then
+values, as if they had been received correctly.  The decoder then
 proceeds to determine whether the remaining message and parity bits
 are consistent with the hypothesized AP bits.  If a codeword is found
 that the decoder judges to have high (but not overwhelmingly high)
 probability of being correct, a ? character is appended when the
-decoded message is displayed. Decodes thus marked are not sent to
-{pskreporter} to avoid occasional misleading spots of false decodes.
+decoded message is displayed.  To avoid misleading spots of occasional 
+false decodes, messages so marked are not forwarded to {pskreporter}.
 
 Successful AP decodes are always labeled with an end-of-line indicator
 of the form aP, where P is one of the single-digit AP decoding types
-listed in Table 1.  For example, an a2 designator says that the
+listed in Table 1.  For example, an `a2` designator says that the
 successful decode used MyCall as hypothetically known information.
 
 [[AP_INFO_TABLE]]
@@ -51,6 +43,23 @@ successful decode used MyCall as hypothetically known information.
 |6 | MyCall DxCall RR73
 |===============================================
 
+Table 2 lists the six possible QSO states that are tracked by the
+WSJT-X auto-sequencer, along with the type of AP decoding that would
+be attempted in each state.
+
+[[AP decoding types for each QSO state]]
+[width="35%",cols="h10,<m20",frame=topbot,options="header"]
+|===========================================
+|State        |AP type
+|CALLING      |   1, 2
+|REPLYING     |   2, 3
+|REPORT       |   2, 3
+|ROGER_REPORT |   3, 4, 5, 6
+|ROGERS       |   3, 4, 5, 6
+|SIGNOFF      |   3, 1, 2
+|===========================================
+
+
 === Decoded Lines
 
 Displayed information accompanying decoded messages generally includes UTC,