Explicitly discuss duplicate mnemonic handling in ~Well
@@ -579,6 +579,13 @@ It remembers the original mnemonic, so when you write the file back out, they co
1669.9 123.45 2550 0.45 123.45 123.45 110.2 105.6
1669.8 123.45 2550 0.45 123.45 123.45 110.2 105.6
+Note that the same approach is taken for duplicate mnemonics elsewhere in
+the header, including the ~Well and ~Parameter sections. So, for example,
+if you have a file which erroneously contains two lines with the UWI mnemonic,
+then attempting to access ``las.well['UWI']`` will fail with a KeyError
+exception, as lasio does not know which of the two mnemonics present should
+be returned.
+
Normalising mnemonic case
~~~~~~~~~~~~~~~~~~~~~~~~~
