Hello diyan9,
iSCSI target name is always either in IQN or EUI format. When we configure the target it needs to be in that format only. For example, in creating IQN style
iqn.yyyy-mm.{reversed domain name}:id_string
you need to have different unique id_string for different disks/LUN's but the format is in type only.
While in Dynamic discovery you provide the server IP/ DNS name of the iSCSI server and the ESXi understands the targets in Static discovery you need to specify the server IP or DNS name, port and the target name in the above format only.
For reference you can check below:
iSCSI - Wikipedia, the free encyclopedia
VMware vSphere 4 - ESX and vCenter Server
Hope this helps .