more text on aliases page

templates/aliases.html

@@ -5,7 +5,7 @@
 
 <h1>Aliases for people's names in {{year}}</h1>
 
-
+<p>This is the list of people on expo this year.
 <table>
 <tr><th>Person</th><th>slug</th><th>aliases</th></tr>
 {% for pe in personexpeditions %}
@@ -17,6 +17,12 @@
 {% endfor %}
 </table>
 
+<p>This table below  lists the possible unambiguous ways of identifying a person in a survex file or a logbook entry. 
+This ridiculously long list of alternatives is derived from what people have actually done in the last 40 years.
+<p>Note that this is year specific: On a year with only one 'Sophie' then the identifier 'Sophie' will be fine. 
+On a year with more than one Sophie, an additional disambiguation is required, such as a surnbame or the first letter of the surname.
+In the case of a year with two people called Ben, both of whose surnames begin with W (yes this has happened),
+the entire surname is required.
 <table>
 <tr><th>alias</th><th>who</th></tr>
 {% for key, value  in aliasdict.items %}
@@ -37,7 +43,8 @@
 {% endfor %}
 </table>
 
-<p>The aliases below are specified in the folk.csv file. Only one alias is possible in that format.
+<p>The aliases below are specified in the folk.csv file. Only one alias is possible in that format. The specified alias ('nickname') 
+is used in the table above to construct possible unambiguous identifiers.
 <table>
 <tr><th>First</th><th>Last</th><th>Full name</th><th>Nickname</th><th>expo first</th><th>expo last</th></tr>
 {% for p in persons %}
@@ -53,6 +60,8 @@
 {% endfor %}
 </table>
 
-
+<p>Don't blame me [programmer] for this, it's just what you all have collectively  done over the decades by using this absurd variety of short-form
+name formats when you have entered the cave data.
+<p>The code that does this is in <var>troggle/parsers/people.py</var>.
 
 {% endblock %}