You asked for it...here goes:
Reference Number Category Code (RNCC)
A code designating the relationship of the Reference Number to the item of supply (ACodP-1 NATO Manual on Codification Sub-Section 553, Table 08)
Reference Number Variation Code (RNVC)
A code to indicate whether the cited Reference Number is or is not item identifying or is for information only (ACodP-1 NATO Manual on Codification Sub-Section 553, Table 12).
DF= Canadian Armed Forces
NCAGE = NATO Commercial and Governmental Entity. This was originally a 5 digit number but has now been expanded to numbers and letters to designate a manufacturer or a supplier.
RNCC=3
Design Control Reference. The primary number used to identify an item of production or a range of items of production, by the manufacturer (individual, company, firm, corporation, or government activity) which controls the design, characteristics, and production of the item by means of its engineering drawings, specifications and inspection requirements.
RNVC=2
A Design Control Reference or other Reference Number that is an item-identifying number for an item of production, or is either a source control reference, a specification or a standard part, type, or similar Reference Number that is an item identifying number for an item of supply.
L0278 =DIRECTORATE OF DISPOSAL, SALES,^ARTEFACTS AND LOANS
48162 = RIFLE,ENFIELD NO 4 MK I, .303 CAL,MODIFIED TO SPORTING MODEL FOR SURVIVAL KIT,42 IN. O/A LG,W/5 SHOT MAGAZINE STOCK FITTED W/RECOIL PAD
It is my guess the this will be a reference number assigned by DHH to account for the EAL survival rifles, which are presently held in the NSN system as 1005-21-808-9499 and will be issued to museums as 9915-20-A01-4314