Every coin that can be merge mined with LTC, needs to have it's own ChainID.
I will keep a list in this topic.
If you are the maintainer of a scrypt-coin and you want to allow your coin to be merge mined against LTC (or same PoW), please propose an unused ChainID below, I will add it to this list. Let's limit the ChainID to 8 bits for now, the protocol allows for 14 bits.
--- 0 reserved
USC 1 UnitedScryptCoin
HUC 2 Huntercoin
BSS 4 Bosscoin
RSV 7 ReserveCoin
ORG 8 Orgcoin
BUR 32 Burbucoin
TPC 36 Templecoin
SPH 53 Sapphire
PST 71 PesetaCoin
LEAF 77 Leafcoin
KAR 87 KarpelesCoin
MIM 134 MagicInternetMoney
Want to know how to implement merged mining for your coin? Take a look at the merged-mining branch of
unitedscryptcoin.git. It contains recent Litecoin + (disabled) merged mining patches. To enable merged mining for your coin, you need to merge with this branch (if possible), set the ChainID and set the starting block.
Addendum: note that the merged-mining patch messes up your block header database. A reindex is needed after this patch.