I believe that is the date of manufacture, but thats about all the help I can be.
They are cancellation marks, denoting that the rifle was no longer the property of the Imperial Japanese Army, but had been sold out of service to another country or a training school.
ukrifleman
ukrifleman is correct.
Those markings are very common, and indicate the rifle has been removed from military service.
About 100,000 Type 30 and Type 38 rifles were removed from service and sold to England during the early years of WWI, they mostly ended up in Russia and in Finland.
Also after WWI, many older Type 38 rifles were removed from military service and delegated for training at secondary schools and colleges during the 1920's and 1930's.
Look at the serial number on the left side of the receiver.
If it is a school training rifle it will have 000 added in front of the serial number. I have a type 38 so marked with 000 added in a different font ahead of the SN.
EDG
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
BR | Bench Rest | M | Magnum | RN | Round Nose |
BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
GC | Gas Check |