Confidential informant identities

Identifies documents containing references to confidential informant identities in Australian contexts. This information type is classified as personally identifiable information under the Privacy Act 1988.

Type

regex

Engine

boost_regex

Confidence

medium

Confidence justification

category-aware structural regex with anchor and context constraints replaces phrase-only detection. Added context gating and exclusion rules improve precision and reduce incidental matches.

Detection quality

Mixed

Jurisdictions

global

Regulations

AML/CTF Act (Cth), IPA 2009 (Qld), NDB Scheme (Cth), Privacy Act 1988 (Cth)

Frameworks

ISO 27001

Data categories

government-id, pii

Scope

wide

Platform compatibility

Purview: Compatible, GCP DLP: Compatible, Macie: Compatible, Zscaler: Compatible, Palo Alto: Degraded, Netskope: Unsupported

Pattern

(?is)\b(?:confidential\s+informant|informant\s+identity|human\s+source|covert\s+source|registered\s+informant|source\s+handler|intelligence\s+source|protected\s+identity|informant\s+file|law\s+enforcement|source\s+management|covert\s+intelligence)\b

Corroborative evidence keywords

confidential informant identities, confidential, informant, identities, law, enforcement, justice, embargoed, embargo, draft not for circulation, for authorized recipients only, for authorised recipients only, not for distribution, not for publication, do not distribute, do not forward, field, column, row, entry (+25 more)

Proximity: 300 characters

Should match

• confidential informant — Primary topic phrase match
• informant identity — Case-insensitive topic phrase match
• human source — Alternative topic phrase match
• covert source — Additional topic phrase match

Should not match

• unrelated generic text without domain phrases — No relevant topic phrases present
• placeholder value 12345 — Random text should not match topic-specific regex
• mugshot victim — Generic word pair from old broad template should not match

Known false positives

• Common words and phrases related to confidential informant identities appearing in policy documents, training materials, HR templates, or compliance guidelines without actual personal data. Mitigation: Require corroborative evidence keywords within the proximity window to confirm sensitive data context rather than general discussion.
• In Australian English, similar terminology used in formal or administrative contexts (education, professional documentation) that does not constitute sensitive data collection. Mitigation: Layer with additional contextual signals such as structured identifiers, form fields, or database column headers to distinguish sensitive records from general references.
• High-frequency pattern matches in large document corpora due to broad regex anchors. Expected match rate is significantly higher than specific identifier patterns. Mitigation: Tune confidence thresholds for bulk scanning. Consider using this pattern primarily as a pre-filter with secondary validation.

References

• https://www.afp.gov.au/
• https://www.legislation.gov.au/C2004A01152/latest/text
• https://www.legislation.gov.au/C2004A03712/latest/text