Very recently (Friday) Istanbul Atatürk APT / LTBA / IST opened a stretch to the souther terminal wing and associated new stands.
Valid on Saturday, not depicted on Jepps maps, no NOTAM, no ATIS. Still no big deal after all.
The new extension is on southern east(bound)
terminal sector. Jepps end at stand 218 and so it follows up to stand 222. Access via "F" from both directions, follow-me to the uncharted stands provided swiftly upon request Yesilkoy Ground 121.8. Not really necessary. Some problems with AGNIS with us, but these are sure resolved by now.
INS cooridnates not available by Saturday morning on our resources, however the relevant wing is west-east aligned, so one may just extrapolate the longitude cooridnates available for the best fit.
Enjoy,
FD.