[bothmob_XXX, (mapid, how_many, respawn_time, (
mapid,
portalid))] = (x, y, z), (mob_id)
Those two are used when you want a mob death opens a portal.
Examples:
-When you kill Exiel's guardians and that opens the next portal in caelum sacra.
-When you kill an altar in D-Water and that opens the portal to jungle/desert
The same 'portalid' value must be present in the svmap por that portal.
In your case 100,2000 are just random values that do nothing, I asume they can't be zero, so ppl use 100-2000
More info about that here: