Adjusted pattern -- more readable without double-escape.

import/marc.properties

@@ -85,7 +85,7 @@ dewey-raw = 082a:083a
 
 # Extract the numeric portion of the OCLC number using a pattern map:
 oclc_num = 035a, (pattern_map.oclc_num)
-pattern_map.oclc_num.pattern_0 = \\([Oo][Cc][Oo][Ll][Cc]\\)[^0-9]*[0]*([0-9]+)=>$1
+pattern_map.oclc_num.pattern_0 = [(][Oo][Cc][Oo][Ll][Cc][)][^0-9]*[0]*([0-9]+)=>$1
 pattern_map.oclc_num.pattern_1 = ocm[0]*([0-9]+)[ ]*[0-9]*=>$1
 pattern_map.oclc_num.pattern_2 = ocn[0]*([0-9]+).*=>$1
 pattern_map.oclc_num.pattern_3 = on[0]*([0-9]+).*=>$1