7 calls to system_region_list() in Drupal 6

block_admin_display_form in modules/block/block.admin.inc

Generate main blocks administration form.

system_default_region in modules/system/system.module

Get the name of the default region for a given theme.

system_initialize_theme_blocks in modules/system/system.module

Assign an initial, default set of blocks for a theme.

template_preprocess_block_admin_display_form in modules/block/block.admin.inc

Process variables for block-admin-display.tpl.php.

template_preprocess_page in includes/theme.inc

Process variables for page.tpl.php

_block_compare in modules/block/block.admin.inc

Helper function for sorting blocks on admin/build/block.

_block_rehash in modules/block/block.module

Update the 'blocks' DB table with the blocks currently exported by modules.