write-only code
Write-only code is an ironic way of describing programming code that is hard to read. The term is a play on read-only memory (ROM). The implication is that the code is so complicated or so poorly structured that not even the person who wrote it will ever be able to modify it. Complex programming languages, such as C and APL, are sometimes referred to as write-only languages, implying that any programs written in them are automatically write-only code.