diff --git a/src/spec.cr b/src/spec.cr
index bf1cc34..27f7e3b 100644
--- a/src/spec.cr
+++ b/src/spec.cr
@@ -101,7 +101,7 @@ class Specs
 	end
 
 	def parse_list(header : String, content : Array(String))
-		name = /[a-zA-Z][a-zA-Z0-9]*/.match(header).try &.[0]
+		name = /[a-zA-Z][a-zA-Z0-9-_]*/.match(header).try &.[0]
 		# puts "new list: #{name}"
 
 		list = Array(String).new
@@ -130,7 +130,7 @@ class Specs
 	end
 
 	def parse_code_block(header : String, content : Array(String))
-		name = /[a-zA-Z][a-zA-Z0-9]*/.match(header).try &.[0]
+		name = /[a-zA-Z][a-zA-Z0-9-_]*/.match(header).try &.[0]
 		# puts "new code block: #{name}"
 
 		value = String.build do |str|
@@ -159,7 +159,7 @@ class Specs
 	end
 
 	def parse_section(header : String, content : Array(String))
-		results = /^[%]([a-zA-Z][a-zA-Z0-9]*)[ \t]*([^#]*)/.match(header)
+		results = /^[%]([a-zA-Z][a-zA-Z0-9-_]*)[ \t]*([^#]*)/.match(header)
 		name = results[1]? if results
 		options = results[2]? if results
 
@@ -241,31 +241,23 @@ class Specs
 	end
 
 	def parse_lines(content : Array(String))
-		count = 0
-
 		while line = content.shift?
 			case line
-			when /^[ \t]*$/
-			else
-				# puts "line #{count}: #{line}"
-			end
-
-			case line
-			when /^[a-zA-Z][a-zA-Z0-9]*:[ \t]*([#].*)?$/
+			when /^[a-zA-Z][a-zA-Z0-9-_]*:[ \t]*([#].*)?$/
 				parse_list line,  content
-			when /^[a-zA-Z][a-zA-Z]*:[ \t]+[^#]+/
+			when /^[a-zA-Z][a-zA-Z0-9-_]*:[ \t]+[^#]+/
 				parse_assignment line
-			when /^[@][a-zA-Z][a-zA-Z]*[ \t]*([#].*)?/
+			when /^[@][a-zA-Z][a-zA-Z0-9-_]*[ \t]*([#].*)?/
 				parse_code_block line, content
-			when /^[%][a-zA-Z][a-zA-Z]*[ \t]*([#].*)?/
+			when /^[%][a-zA-Z][a-zA-Z0-9-_]*[ \t]*([#].*)?/
 				parse_section line, content
 			when /^[ \t]*#/
 				# puts "comment"
-			when /^[ \t]+/
-				puts "tab!! should not happen"
+			when /^[ \t]+$/
+				# puts "empty line"
+			when /^[ \t]+[^ \t#]/
+				raise "line starting with spaces or a tabulation outside a list or a section: should not happen"
 			end
-
-			count += 1
 		end
 	end