Fetching unique values from file

After giving

grep -A4 "feature 1," <file name>

I have extracted the following text

        feature 1,
        subfeat 2,
        type 1,
        subtype 5,
        dump '30352f30312f323030392031313a33303a3337'H  -- "05/01/2009 11:30:37" \--

--

        feature 1,
        subfeat 0,
        type 3,
        subtype 1,
        value 0,

--

        feature 1,
        subfeat 2,
        type 1,
        subtype 5,
        dump '30352f30312f323030392031313a33303a3336'H  -- "05/01/2009 11:30:36" \--

But here the section

feature 1,
subfeat 2,
type 1,
subtype 5,
dump '30352f30312f323030392031313a33303a3336'H -- "05/01/2009 11:30:36"
is appearing twice.I want it to show up only once.Is there a way to do that?

Could you post a sample of you real data (not the filtered output) an example of the desired output?