DOC: Improve in-code documentation

src/main/java/org/caosdb/server/jobs/core/CheckParValid.java

@@ -67,8 +67,8 @@ public class CheckParValid extends EntityJob {
           if (parent.hasId()) {
             // check parent by id
             if (!parent.getId().isTemporary()) {
-              // id >= 0 (parent is yet in the database)
-              // retrieve parent by id
+              // id isn't temporary, i.e., parent is already in the database and
+              // can be retrieved by id
               final EntityInterface foreign = retrieveValidSparseEntityById(parent.getId(), null);
               // check permissions for this
               // parentforeign.acceptObserver(o)