The board in /secure/room/arch.c does not function.
Its existing code,
SetInventory( ([
"/secure/obj/arch_board" : 1,
]) );
should be more like
object o_board;
o_board = new( "/secure/obj/arch_board" );
o_board->SetKeyName( "messageboard" );
o_board->SetId( ({ "board", "messageboard", "message board", "arch board" }) );
o_board->set_board_id("arch_board");
o_board->set_max_posts( 50 );
o_board->SetShort( "the arch message board" );
o_board->eventMove( this_object() );
(without the extra configuration items, no file for it was showing up in /secure/save/boards...)
set_board_id() is probably the key item, there, really...