GPT-3.5 / GPT-4

Truncated handle of Redditor davidjl123, another r/counting counter. Unusually, it is anomalous under both r50k and the newer cl100k tokenizer.

One of only three Category-A “unspeakable” tokens Adam Yedidia found in the top 2,000 of the cl100k vocabulary; likely a Smarty templating-engine fragment that never appeared in GPT-3.5/4 training data.

The second of Yedidia's three Category-A unspeakable cl100k tokens (alongside SmartyHeaderCode and ` davidjl`).

A C#-compiler-flavored fragment (“can be converted to foreach”) that became the most famous “polysemantic” glitch token: the model perceives it as a different word every time. It exists in cl100k, Llama-3 and Qwen vocabularies because the tokenizers share BPE merges.

A bison/yacc parser identifier that is “polysemantic” for ChatGPT — perceived as a different word each time; recommended by Watkins as one of the most interesting tokens to play with.

A JS-reflection-style identifier in the polysemantic class; another of Watkins' recommended tokens.

A misspelling-ish fragment of “hexatrigesimal” (base-36); a polysemantic unspeakable token.

A Dutch postal-code API fragment that is glitchy across three separate model families — a good demonstration that glitch tokens transfer whenever tokenizers share BPE merges.

The second member of the ForCanBeConverted triplet (cl100k id 80370) — a single C#-compiler-flavored fragment that BPE split into three adjacent tokens (80369–80371).

The third member of the ForCanBeConverted triplet (cl100k id 80371), the form that spells out “can be converted to foreach” in full.

A C# LINQ-flavored identifier (cl100k id 73016), adjacent to StreamLazy (73018).

A C# LINQ-flavored identifier (cl100k id 73018), adjacent to EnumerableStream (73016).

An identifier fragment of unknown origin (cl100k id 79260).

Suspected fragment of a scalablytyped-style identifier (cl100k id 81998).

The sibling of the cataloged $PostalCodesNL without the $ prefix (cl100k id 85069) — a Dutch postal-code API fragment.

Suspected to be the name of the Python compiler Nuitka (cl100k id 75520).

Suspected GitHub username of japgolly, a Scala library author (cl100k id 70784).

A C++-style identifier whose misspelling (“Intialized”, missing the second i) is part of the token itself (cl100k id 82929).

A C#-flavored identifier fragment (cl100k id 89471) and head of the useRal triplet (useRal/useRalative/useRalativeImagePath) — Watkins flagged the triplet phenomenon itself as worth investigating. Also verified as under-trained in OLMo 2 by Magikarp.

An identifier fragment in cl100k, likely the stem of a type name such as “TemporalType”.

A C++ GUID-style identifier fragment (cl100k id 87551).

A naming fragment from nil-bundle checks in iOS/Mac development (cl100k id 86415).

Fragment of the Qt framework's AWS module name (cl100k id 93905, with a leading space).

Fragment of the PHP Propel ORM's exception class name (cl100k id 86393, with a leading space).

The second member of the useRal triplet (cl100k id 89472), a C#-flavored identifier fragment; the same string also exists in the Qwen2 vocabulary.