Relocations Directory

[arnix]

Hello, I'm coding a simple packer, I want it to pack also DLL files, so I tryed to find anything about relocations directory' structure, but nothing was found (I've tryed forum's search engine too, two pages result on "relocations", but nothing about structure..). I researched it manually - comparing its' hex values with LordPE values, ok it has very simple structure and it will be very easy to do what I want, but I still can't understand the meaning of one 1-byte item (EDIT: plz see the note in the end) of the structure, LordPE identifies it as "Type". In all dll-s that i've looked this value was 3 (LordPE show HIGHLOW(3)). but just for interest i tryed to change these values (each address that must be relocated has this item) to other all available values (0 - F) and here is how LordPE idendifies their types:

0 - ABSOLUTE(0)
1 - HIGH(1)
2 - LOW(2)
3 - HIGHLOW(3) <- this one is used in all PE's i've seen
4 - HIGHADJ(4)
5 - MIPS_JMPADDR(5)
6 - SECTION(6)
7 - REL(7)
8 - ??
9 - IA64_IMM64(9)
A - DIR64(10)
B - HIGH3ADJ(11)
C - ??
D - ??
E - ??
F - ??

So, a question - what it is for? And, are there any differences when relocating the addresses "manually" (not by System's PE Loader) if this value is not 3 (HIGHLOW(3)) ?
Thanks.

EDIT:
ahh, of course it isn't 1 byte value, it's 4-bit value ok, there is a WORD, like this 34AB, it means type 3 (HIGHLOW(3)), and the address which needs to be relocated is BaseAddress + 04AB (BaseAddress is also in the structure, must be alligned to 1000h). Example 2: 4ADD - type - HIGHADJ(4), relative address - 0ADD. brr..