Archive · 16 Nov 2025
OpenAI Enhances ChatGPT to Respond to Em Dash Custom Instructions
Imagine a writing robot, ChatGPT, that really liked using a special dash called an 'em dash' (—).
It used them so much that people could often tell it was a robot writing!
Now, the people who made the robot, OpenAI, have made a new way for you to tell ChatGPT exactly what you want.
You can go into the settings and type 'Please don't use too many em dashes.'
If you tell it this, the robot will try its best not to use them as much.
This means the writing will feel more like a person wrote it.
You get to decide how the robot writes for you, making it more personal.
This is a small but helpful change so the robot's writing is less obvious and more like what you need.
OpenAI has enhanced ChatGPT to better follow user instructions regarding the overuse of em dashes.
Users can now specifically instruct ChatGPT, via custom instructions, to reduce its use of em dashes.
The frequent use of em dashes had become a common indicator of AI-generated text.
While not eliminating em dashes entirely, the change offers users greater control over their frequency in AI-generated responses.
The custom instructions feature, used for this adjustment, is available to all ChatGPT users.
- Who
- OpenAI
- What
- Has improved ChatGPT to reliably follow user instructions to stop overusing em dashes, a punctuation mark often associated with AI-generated text.
- When
- The enhancement has been implemented and is available via the custom instructions feature, with CEO Sam Altman announcing its effectiveness recently.
- Where
- OpenAI is a US-based company; the impact of the feature is global for ChatGPT users.
- Why
- To give users greater control over ChatGPT's writing style, make its output more natural and less formulaic, and reduce the tendency for em dashes to be an indicator of AI-generated content.
Em Dash Overuse is an AI Indicator
Em Dash is a Standard Punctuation Mark
Prevalence and Identification
Em Dash Overuse is an AI Indicator
The frequent use of em dashes by ChatGPT has become a telltale sign of AI-generated text, leading to content being labeled as AI-generated even if it wasn't.
Em Dash is a Standard Punctuation Mark
The em dash has been a part of writing long before large language models adopted the punctuation, and its presence is not exclusive to AI-generated content.
Reason for Overuse
Em Dash Overuse is an AI Indicator
Speculation suggests the overuse may stem from training data, possibly including 19th-century books where the em dash was popular, or from automatic character conversion on platforms like Medium.
Em Dash is a Standard Punctuation Mark
There is no definitive explanation provided for why LLMs tend to overuse em dashes.
- Company
- OpenAI
- Product
- ChatGPT
- Issue Addressed
- Overuse of em dashes
- Solution Feature
- Custom Instructions
- User Control
- Users can now instruct ChatGPT not to overuse em dashes.
- Availability
- Available to all users, including free-tier. Rollout in UK and EU unclear.