A delimiter is a character or sequence of characters that separates portions of text or data. In prompts, delimiters distinguish instructions, rules, examples, source data, code, and existing outputs so an LLM can interpret their roles more clearly. section 2.4.2 section 2.8
Use delimiters to make prompt structure explicit:
- Separate the task description from the data to process, such as placing a user story between three hash marks. section 2.4.7
- Define a small notation system for structured data, such as # for a table, % for columns, and | for column properties. section 2.4.2 section 6.1.1
- Keep multiple inputs distinct, such as separating a user story from an existing risk list or existing test cases. section 8.1.1 section 5.4
- Mark code boundaries clearly and instruct the model to preserve the delimited code rather than changing it. section 4.2.2 section 4.5.1
Delimited SQL data-generation prompt
You are a SQL data generator. Generate five rows for a MySQL database. Interpret # as the table name, % as a column, and | as the sequence of column name, data type, and options. If an option says random, randomize the value. # rooms % room_name | string | random % type | string | 'single' or 'double' % beds | integer | 1 to 6 % accessible | boolean | true or false % roomPrice | integer | 100 to 200. The same notation can be modified to add requirements such as room_size. The resulting rows can then be checked against the requested types, ranges, and relationships. section 2.4.2
###
public BookingResult createBooking(Booking bookingToCreate) throws
➥SQLException {
if(dateCheckValidator.isValid(bookingToCreate.getBookingDates())) {
if (bookingDB.checkForBookingConflict(bookingToCreate)) {
return new BookingResult(HttpStatus.CONFLICT);
} else {
CreatedBooking createdBooking =
➥bookingDB.create(bookingToCreate);
if(bookingToCreate.getEmail() != null &&
➥bookingToCreate.getPhone() != null){
MessageBuilder messageBuilder = new MessageBuilder();
Message message = messageBuilder.build(bookingToCreate);
messageRequests.postMessage(message);
}
return new BookingResult(createdBooking,
➥HttpStatus.CREATED);
}
} else {
return new BookingResult(HttpStatus.CONFLICT);
}
}
###
Inspect the triple-hash boundary around Java code and compare it with the requested risk-analysis instructions. section 4.2.2
Delimiters improve clarity and make prompts easier to reconfigure, but they do not guarantee correct output. Generated data can still contain weak assumptions, invalid relationships, or placeholder URLs, so humans must verify results against requirements. section 2.4.2 section 6.1.1 section 2.8
