HSV v1.0

Hierarchical Separated Values

HSV is both a file format (like CSV) and a streaming protocol. HSV is a carefully curated set of primary control codes standardized for modern use. In 1963, ASCII defined these characters for structured data (like JSON)—then we forgot about them and spent 60 years escaping quotes instead. No escaping. No quotes. All of Unicode is valid data, and binary mode handles raw bytes. It streams, and parsing parallelizes trivially.

CSV  →  1 level    (comma, quoting required)
JSON →  unlimited  (escaping required)
HSV  →  unlimited  + framing + protocol (no escaping)

Where It Fits

Save .hsv files and grep them, or stream records over a socket with acknowledgments. Binary formats like MessagePack and Protobuf are serialization-only.

	HSV	CSV	JSON	MsgPack	Protobuf
File format	✓	✓	✓	✗	✗
Hierarchy	Unlimited	1 level	Unlimited	Unlimited	Unlimited
Text tools work	✓	✓	✓	✗	✗
No escaping	✓	Quoting	✗	✓	✓
Streaming	✓	Lines	✗	✓	✓
Framing (STX/ETX)	✓	✗	✗	✗	✗
Protocol (ACK/NAK)	✓	✗	✗	✗	✗

HSV is CSV with hierarchy, JSON without escaping, and unlike binary-only formats, you can debug with cat and grep.

Structure

key ␟ value                       key-value pair
pair ␞ pair ␞ pair                object
item ␝ item ␝ item                array
key ␟ ␎ nested ␏                  unlimited nesting (SO/SI)
␂ record ␜ record ␃               stream

Comparison with JSON

JSON (46 bytes)

{"name": "Alice", "age": "30", "city": "NYC"}

HSV (27 bytes)

name␟Alice␞age␟30␞city␟NYC

40% smaller. No quotes, braces, colons, or commas.

Escaping

JSON (escaping required)

{"msg": "He said \"hello\""}

HSV (no escaping)

msg␟He said "hello"

Newlines

JSON (must escape)

{"text": "line 1\nline 2"}

HSV (literal)

text␟line 1
line 2

Streaming

STX/ETX framing solves the streaming problem:

␂name␟Alice␞role␟admin␜name␟Bob␞role␟user␃

Unlike NDJSON, newlines in data don't break parsing. Unlike length-prefix, it's human-inspectable.

Headers

SOH (Start of Header) adds metadata before the data block:

␁hsv␟1.0␞content-type␟users␂name␟Alice␞role␟admin␃

Structure: ␁ header ␂ data ␃ — header properties use the same format as data. When present, hsv␟1.0 is the recommended first property for version identification.

Mixed Content

Everything outside STX…ETX is ignored—no special comment syntax needed:

This text is ignored
␂name␟Alice␞age␟30␃
So is this

Binary Mode

DLE (Data Link Escape) enables raw binary in values:

␐␂ [any bytes] ␐␃     binary section
␐␐                     literal DLE byte

Inside binary mode, only DLE needs escaping. All other bytes—including the 7 structure separators—are literal data. ~0.4% overhead for random binary.

type␟image␞data␟␐␂<raw PNG>␐␃␞width␟800

This is BISYNC-style transparency from 1967, finally applied to data serialization.

Implementations

Reference implementations in Rust and Python:

github.com/LingenicLLC/HSV

The Eighteen Control Codes

Eighteen invisible bytes reserved. Everything else is data.

Code	Hex	Name	Purpose
Framing
1	0x01	SOH	Start header
2	0x02	STX	Start data block
3	0x03	ETX	End data block
4	0x04	EOT	End stream
Protocol
5	0x05	ENQ	Enquiry (request ACK)
6	0x06	ACK	Acknowledge (success)
21	0x15	NAK	Negative acknowledge (error)
24	0x18	CAN	Cancel operation
Flow Control
17	0x11	XON	Resume transmission
19	0x13	XOFF	Pause transmission
22	0x16	SYN	Sync/keepalive
Nesting
14	0x0E	SO	Start nested structure
15	0x0F	SI	End nested structure
16	0x10	DLE	Binary mode escape
Structure
28	0x1C	FS	Record separator
29	0x1D	GS	Array element separator
30	0x1E	RS	Property separator
31	0x1F	US	Key-value separator

Tools may display control codes as: ␁ ␂ ␃ ␄ ␅ ␆ ␎ ␏ ␐ ␑ ␓ ␕ ␖ ␘ ␜ ␝ ␞ ␟

Quick Reference

Reserved:  0x01-0x06 0x0E-0x11 0x13 0x15-0x16 0x18 0x1C-0x1F  (18 bytes)
Data:      Everything else (all of Unicode)

Structure:
  ␟ (US)   key:value
  ␞ (RS)   properties
  ␝ (GS)   array items
  ␜ (FS)   records

Framing:   ␁...␂...␃  (SOH header, STX data, ETX end)
Nesting:   ␎...␏  (SO/SI, unlimited depth)
Binary:    ␐␂...␐␃  (DLE transparency)
Protocol:  ␅/␆/␕  (ENQ/ACK/NAK)
Flow:      ␑/␓/␖  (XON/XOFF/SYN)
Stream:    ␄  (EOT end of stream)

Extension: .hsv
MIME type: application/hsv