diff --git a/docs/EN/UsefulLinks/Glossary.md b/docs/EN/UsefulLinks/Glossary.md
index f1479eb05122..4572b88e5be5 100644
--- a/docs/EN/UsefulLinks/Glossary.md
+++ b/docs/EN/UsefulLinks/Glossary.md
@@ -85,6 +85,8 @@ Insulin active in the user’s body.
 __ISF__ = Insulin Sensitivity Factor.
 The expected decrease in BG as a result of one unit of insulin.
 
+__Keystore (or JKS)__ = a Java Key Store which is an encrypted file where your personal developer certificates and keys will be stored required for your __AAPS'__ build (and rebuid).
+
 __LGS__ = Low Glucose Suspend. 
 __AAPS__ will reduce basal if __BG__ is dropping and if __BG__ is rising, then it will only increase basal if  __IOB__ is negative (from a previous __LGS__), otherwise basal rates will remain the same as the user’s selected __Profile__. The user may temporarily experience spikes following treated hypos without the ability to increase basal on the rebound. → see also objective 6.