issue25 [NOTE]: comment regarding time correction field

issue25-libdatrwxx-miniseed-consistency-checks.txt

@@ -3,6 +3,30 @@ this is <issue25-libdatrwxx-miniseed-consistency-checks.txt>
 libdatrwxx: MiniSEED consistency checks
 ---------------------------------------
 
+Final note:
+
+Without data which would use the time correction field in the Fixed
+Section of Data Header I cannot test the mechnism for consistency.
+
+The SEED Manual itself is not fully conclusive in this respect:
+
+On page 108 of "SEED Reference Manual, Standard for the Exchange of Earthquake
+Data, SEED Format Version 2.4, August, 2012":
+
+note 16: LONG: Time correction. This field contains a value that may modify
+  the field 8 record start time. Depending on the setting of bit 1 in field
+  12, the record start time may have already been adjusted. The units are in
+  0.0001 seconds.
+
+The correction field accordingly may carry a sign. It is implemented in
+datrw::mseed::SEED::FixedDataRecordHeader as "int tcorr". It is applied
+accordingly in libtime::TAbsoluteTime datrw::mseed::MiniSEEDRecord::date()
+
+The SEED Manual misses to define whether the correction should be added or
+subtracted.
+
+----------------------------------------------------------------------------
+
 As a reminder:
 - check application of time correction before finishing this issue
   time correction is not part of this issue, however Chad Trabant has made a