Asandwichpoem Poem by Francis Duggan

What is a sandwich poem can someone tell me
It is not complimentary is how it seems to be
Perhaps a twenty first century term for doggerel
So many do write but not all does write well
From my life's experiences i have come to realize
There are the non offensive and those who criticize
Some people's comments to curiosity gives rise
But then everyone grows older but few does grow wise
Of some modern terminologies my curiosity grow
What a sandwich poem means i would like to know
It is a term lexicographers does not recognize
But this in itself is not any surprise
Not complimentary in any way is how it does seem
Or meant for to bolster one's low self esteem.