+
+Rank tweak: follow=number will increase mult by number if two terms
+occur next to each other; number-1 if they are one term apart , .. 0
+if they are number a part (all in order). Default is 0 (following
+terms has no effect).
+
+Rank tweak: lead=number will increase mult by number if term is first
+term in field, number-1 if second, ... 0 if term is at offset
+number of more. Default value is 0 (position irrelevant).
+
+Rank tweak: length=strategy. length="linear" if mult is to be divided
+by length (existing, default behavior), length="log" if mult is to be
+divided by log2(1+length), length="none" if mult is not to be affected
+by length.
+
--- 1.6.20 2012/09/21
Rank algorithm details may be printed as part of show reseponse in
Record as returned by show/record command have a minimal indentation
which makes things human-readable.
+New configuration of default sorting criteria (sort-default) in
+service definition. If no criteria is defined it will be as before
+'relevance'.
+
+Search command now supports sort parameter just as the show command.
+If no parameter is give, it will use the service sort-default value.
+
--- 1.6.19 2012/09/18
Rank algorithm skips strings that gets normalized to empty string.