diff --git a/lib/ebnf/peg/parser.rb b/lib/ebnf/peg/parser.rb
index bac73d0..704e333 100644
--- a/lib/ebnf/peg/parser.rb
+++ b/lib/ebnf/peg/parser.rb
@@ -138,6 +138,8 @@ def start_production(term, **options, &block)
       # @yieldparam [Proc] block
       #   Block passed to initialization for yielding to calling parser.
       #   Should conform to the yield specs for #initialize
+      # @yieldparam [Hash] **options
+      #   Other data that may be passed to the production
       # @yieldreturn [Object] the result of this production.
       # Yield to generate a triple
       def production(term, clear_packrat: false, &block)
@@ -183,6 +185,8 @@ def method_missing(method, *args, &block)
     #   Identify the symbol of the starting rule with `start`.
     # @param  [Hash{Symbol => Object}] options
     # @option options[Integer] :high_water passed to lexer
+    # @option options[:upper, :lower] :insensitive_strings
+    #   Perform case-insensitive match of strings not defined as terminals, and map to either upper or lower case.
     # @option options [Logger] :logger for errors/progress/debug.
     # @option options[Integer] :low_water passed to lexer
     # @option options[Boolean] :seq_hash (false)
@@ -201,7 +205,7 @@ def method_missing(method, *args, &block)
     #   or errors raised during processing callbacks. Internal
     #   errors are raised using {Error}.
     # @todo FIXME implement seq_hash
-    def parse(input = nil, start = nil, rules = nil, **options, &block)
+    def parse(input = nil, start = nil, rules = nil, insensitive_strings: nil, **options, &block)
       start ||= options[:start]
       rules ||= options[:rules] || []
       @rules = rules.inject({}) {|memo, rule| memo.merge(rule.sym => rule)}
@@ -230,7 +234,7 @@ def parse(input = nil, start = nil, rules = nil, **options, &block)
       start_rule = @rules[start]
       raise Error, "Starting production #{start.inspect} not defined" unless start_rule
 
-      result = start_rule.parse(scanner)
+      result = start_rule.parse(scanner, insensitive_strings: insensitive_strings)
       if result == :unmatched
         # Start rule wasn't matched, which is about the only error condition
         error("--top--", @furthest_failure.to_s,
@@ -367,21 +371,17 @@ def debug(*args, &block)
     # Start for production
     # Adds data avoiable during the processing of the production
     #
+    # @param [Symbol] prod
+    # @param [Hash] **options other options available for handlers
     # @return [Hash] composed of production options. Currently only `as_hash` is supported.
     # @see ClassMethods#start_production
-    def onStart(prod)
+    def onStart(prod, **options)
       handler = self.class.start_handlers[prod]
       @productions << prod
-      progress("#{prod}(:start)", "",
-        lineno: (scanner.lineno if scanner),
-        pos: (scanner.pos if scanner)
-      ) do
-          "#{prod}, pos: #{scanner ? scanner.pos : '?'}, rest: #{scanner ? scanner.rest[0..20].inspect : '?'}"
-      end
       if handler
         # Create a new production data element, potentially allowing handler
         # to customize before pushing on the @prod_data stack
-        data = {_production: prod}
+        data = {_production: prod}.merge(options)
         begin
           self.class.eval_with_binding(self) {
             handler.call(data, @parse_callback)
@@ -396,14 +396,21 @@ def onStart(prod)
         # explicit start handler
         @prod_data << {_production: prod}
       end
+      progress("#{prod}(:start)", "",
+        lineno: (scanner.lineno if scanner),
+        pos: (scanner.pos if scanner)
+      ) do
+        "#{data.inspect}@(#{scanner ? scanner.pos : '?'}), rest: #{scanner ? scanner.rest[0..20].inspect : '?'}"
+      end
       return self.class.start_options.fetch(prod, {}) # any options on this production
     end
 
     # Finish of production
     #
     # @param [Object] result parse result
+    # @param [Hash] **options other options available for handlers
     # @return [Object] parse result, or the value returned from the handler
-    def onFinish(result)
+    def onFinish(result, **options)
       #puts "prod_data(f): " + @prod_data.inspect
       prod = @productions.last
       handler, clear_packrat = self.class.production_handlers[prod]
@@ -415,7 +422,7 @@ def onFinish(result)
         # Pop production data element from stack, potentially allowing handler to use it
         result = begin
           self.class.eval_with_binding(self) {
-            handler.call(result, data, @parse_callback)
+            handler.call(result, data, @parse_callback, **options)
           }
         rescue ArgumentError, Error => e
           error("finish", "#{e.class}: #{e.message}", production: prod, backtrace: e.backtrace)
diff --git a/lib/ebnf/peg/rule.rb b/lib/ebnf/peg/rule.rb
index 305543a..ba57bf8 100644
--- a/lib/ebnf/peg/rule.rb
+++ b/lib/ebnf/peg/rule.rb
@@ -13,7 +13,7 @@ module Rule
     ##
     # Parse a rule or terminal, invoking callbacks, as appropriate
 
-    # If there is are `start_production` and/or `production`,
+    # If there are `start_production` and/or `production` handlers,
     # they are invoked with a `prod_data` stack, the input stream and offset.
     # Otherwise, the results are added as an array value
     # to a hash indexed by the rule name.
@@ -31,8 +31,9 @@ module Rule
     # * `star`: returns an array of the values matched for the specified production. For Terminals, these are concatenated into a single string.
     #
     # @param [Scanner] input
+    # @param [Hash] **options Other data that may be passed to handlers.
     # @return [Hash{Symbol => Object}, :unmatched] A hash with keys for matched component of the expression. Returns :unmatched if the input does not match the production.
-    def parse(input)
+    def parse(input, **options)
       # Save position and linenumber for backtracking
       pos, lineno = input.pos, input.lineno
 
@@ -71,7 +72,7 @@ def parse(input)
       else
         eat_whitespace(input)
       end
-      start_options = parser.onStart(sym)
+      start_options = options.merge(parser.onStart(sym, **options))
       string_regexp_opts = start_options[:insensitive_strings] ? Regexp::IGNORECASE : 0
 
       result = case expr.first
@@ -84,7 +85,7 @@ def parse(input)
           when Symbol
             rule = parser.find_rule(prod)
             raise "No rule found for #{prod}" unless rule
-            rule.parse(input)
+            rule.parse(input, **options)
           when String
             s = input.scan(Regexp.new(Regexp.quote(prod), string_regexp_opts))
             case start_options[:insensitive_strings]
@@ -148,7 +149,7 @@ def parse(input)
       when :plus
         # Result is an array of all expressions while they match,
         # at least one must match
-        plus = rept(input, 1, '*', expr[1], string_regexp_opts)
+        plus = rept(input, 1, '*', expr[1], string_regexp_opts, **options)
 
         # Update furthest failure for strings and terminals
         parser.update_furthest_failure(input.pos, input.lineno, expr[1]) if terminal?
@@ -163,7 +164,7 @@ def parse(input)
       when :rept
         # Result is an array of all expressions while they match,
         # an empty array of none match
-        rept = rept(input, expr[1], expr[2], expr[3], string_regexp_opts)
+        rept = rept(input, expr[1], expr[2], expr[3], string_regexp_opts, **options)
 
         # # Update furthest failure for strings and terminals
         parser.update_furthest_failure(input.pos, input.lineno, expr[3]) if terminal?
@@ -176,7 +177,7 @@ def parse(input)
           when Symbol
             rule = parser.find_rule(prod)
             raise "No rule found for #{prod}" unless rule
-            rule.parse(input)
+            rule.parse(input, **options.merge(_rept_data: accumulator))
           when String
             s = input.scan(Regexp.new(Regexp.quote(prod), string_regexp_opts))
             case start_options[:insensitive_strings]
@@ -204,7 +205,7 @@ def parse(input)
       when :star
         # Result is an array of all expressions while they match,
         # an empty array of none match
-        star = rept(input, 0, '*', expr[1], string_regexp_opts)
+        star = rept(input, 0, '*', expr[1], string_regexp_opts, **options)
 
         # Update furthest failure for strings and terminals
         parser.update_furthest_failure(input.pos, input.lineno, expr[1]) if terminal?
@@ -217,7 +218,7 @@ def parse(input)
         input.pos, input.lineno = pos, lineno
       end
 
-      result = parser.onFinish(result)
+      result = parser.onFinish(result, **options)
       (parser.packrat[sym] ||= {})[pos] = {
         pos: input.pos,
         lineno: input.lineno,
@@ -229,7 +230,8 @@ def parse(input)
     ##
     # Repitition, 0-1, 0-n, 1-n, ...
     #
-    # Note, nil results are removed from the result, but count towards min/max calculations
+    # Note, nil results are removed from the result, but count towards min/max calculations.
+    # Saves temporary production data to prod_data stack.
     #
     # @param [Scanner] input
     # @param [Integer] min