hook_update_last_removed()
Return a number which is no longer available as hook_update_N(). If you remove some update functions from your mycustommodule.install file, you should notify Drupal of those missing functions. This way, Drupal can ensure that no update is accidentally skipped.
Parameters
none
Return value
An integer, corresponding to hook_update_N() which has been removed from mycustommodule.install.
Usage sample
function hook_update_last_removed() {
// We've removed the 6.x-1.x version of mycustommodule, including database updates.
// The next update function ismycustommodule_update_6200()
return 6105;
}