Remove one or more blocks, each named by an id or any address geml_list prints; a filter (=== type, {key=value}) removes every block it matches. Each block takes the blank line that separated it from its neighbours, so deleting what geml_add inserted leaves the file as it was. To undo a deletion, geml_revert the removed id; to change a block rather than remove it, use geml_set. References left pointing at a removed block come back as diagnostics but do NOT block the deletion — read them, then repair the references or revert. A selector that names nothing is skipped, so repeating a call changes nothing. Returns {ok, file, diagnostics, revision}, with notes when the write did something to say out loud (a block it dropped, an address it changed); a refusal is ok: false with a hint, and the file is unchanged. This server is STATELESS: the document travels in source and a write comes back as document for you to save; it holds no other documents, so a cross-document reference such as [[other.geml#id]] cannot be resolved here and is reported as unresolvable-document.