  Finding desired information from large data set is a difficult problem.
Information retrieval is concerned with the structure, analysis, organization,
storage, searching, and retrieval of information. Index is the main constituent
of an IR system. Now a day exponential growth of information makes the index
structure large enough affecting the IR system's quality. So compressing the
Index structure is our main contribution in this paper. We compressed the
document number in inverted file entries using a new coding technique based on
run-length encoding. Our coding mechanism uses a specified code which acts over
run-length coding. We experimented and found that our coding mechanism on an
average compresses 67.34% percent more than the other techniques.
