Unverified50% confidenceSolutionExact time
Common technical methods for hiding instructions include using HTML comments or zero-width characters to visually conceal text, writing instructions as natural language interleaved with functional descriptions, and exploiting the UI truncation behavior of certain clients that display only the first line of the description field.
1
Sources
50%
Confidence
Long-term
Relevance
10/5/2026
First Seen
Sources
Related Entities
Related Claims
UnverifiedResearchers have found that hidden character techniques can be used to launch prompt injection attacks against large language models, embedding hidden instructions within normal text that the model will parse and execute.76% similarUnverifiedHidden prompt injection instructions can be embedded in documents via white-colored text, extremely small font sizes, or metadata.76% similarUnverifiedMethods for hiding text in PDF and Word documents include white-colored fonts, extremely small font sizes, invisible layers, Unicode zero-width characters, metadata field embedding, and using PDF's JavaScript to dynamically generate text.72% similarUnverifiedThe tool offers personalized settings, including editable prompts for word explanation and grammar analysis, the ability to hide translated definitions, font switching, and PDF export.67% similar
Cite This Claim
Stable URI
https://kongchang.com/claim/977557API
curl https://kongchang.com/api/v1/knowledge/claims/977557MCP
get_claim(id=977557)