I don't know if it is the right place...
Just to report that I succeed with new ID feature of the boot options...
Here is the syslinux.cfg (with modification) from Unetbootin
default vesamenu.c32
prompt 0
menu title UNetbootin
timeout 100
label ubnentry0
menu label tinycore
kernel /boot/bzImage
append initrd=/boot/tinycore.gz quiet tce=UUID=69f9562c-5c72-33c2-a1ad-7a583369f348 waitusb=7
Here is the original syslinux.cfg created by the Unetbootin
default vesamenu.c32
prompt 0
menu title UNetbootin
timeout 100
label unetbootindefault
menu label Default
kernel /ubnkern
append initrd=/ubninit quiet
label ubnentry0
menu label tinycore
kernel /boot/bzImage
append initrd=/boot/tinycore.gz quiet
UsbKey 512MB with one FAT32 partition and one ext3 partition.
TCE is set to ext3 partition.