For relevant information regarding Map lists, visit Map List.
sv_startmapscript and sv_endmapscript are ways of setting gameplay variables, or CVARS, for the start and end of a map.
A little knowledge of scripting/programming will help when creating map scripts.
if is a widely used conditional statement in both programming and scripting, here is an example on its use in a map script:
if CVAR1 eq VALUE1 CVAR2 VALUE2
Basically, this says "if the value of CVAR1 is equal to VALUE1 then set CVAR2 to VALUE2"
These scripts are entered into either your odasrv.cfg, when odasrv is running by setting sv_startmapscript/sv_endmapscript to the script line, sv_startmapscript and sv_endmapscript can also be set to execute an external file containing a script, for example:
set sv_startmapscript "+exec script.cfg"
Now for an example, say we wanted to set the skill to 3 for the next level at the end of MAP01.
if sv_curmap eq MAP01 SKILL 3
If you wanted to change the hostname of the server when the map changes to MAP30
if sv_curmap eq MAP30 hostname "join if you dare"