ISTR

I seem to recall
Found on http://www.scot-rail.co.uk/page/Glossary

ISTR

I Seem To Recall, details ...
Found on http://www.cryer.co.uk/glossary/i/index.htm

ISTR

I Seem To Remember
Found on http://www.encyclo.co.uk/local/21662

istr

I seem to remember
Found on http://www.noslang.com/dictionary/i/

ISTR

Short for `I seem to recall` (i.e. I'm not really sure) c.f. IIRC
Found on http://www.ruf.rice.edu/~kemmer/Words04/usage/slang_internet.html
No exact match found