Overview
British Library Legal Deposit Crawler is an archiver associated with British Library, used for preserving UK websites under legal-deposit and web-archiving programs.
Its primary user-agent pattern is bl.uk_lddc_bot; related patterns include bl.uk_lddc_bot/3.4.0; UK Web Archive crawler; a representative HTTP user-agent is bl.uk_lddc_bot/3.4.0-20220727 (+https://www.bl.uk/legal-deposit/web-archiving).
British Library Legal Deposit Crawler is Unverified at the identity-evidence level. The listed identity remains useful for detection, but this record does not currently contain authoritative evidence sufficient to authenticate the identity claim.
British Library Legal Deposit Crawler is documented or strongly corroborated as honoring robots.txt directives.
The crawler token is documented by UK archival guidance and repeatedly observed from British Library-controlled infrastructure.
Treat the user-agent as an identity claim. Corroborate it with operator-controlled IP ranges, reverse DNS, signed-request evidence, or current documentation when available.
Identity
- User-Agent Pattern
-
bl.uk_lddc_bot - Aliases
- bl.uk_lddc_bot/3.4.0; UK Web Archive crawler
- HTTP Agent Examples
-
bl.uk_lddc_bot/3.4.0-20220727 (+https://www.bl.uk/legal-deposit/web-archiving) - Robots Token
- bl.uk_lddc_bot
- Identity Type
- Observed
- Evidence Method
- Treat `bl.uk_lddc_bot` as an identity signal only. Confirm it with current operator documentation, cryptographic verification, forward-confirmed reverse DNS, source-network ownership, or other authoritative evidence before trusting the claimed identity.
Classification
- Type
- Archive
- Kind
- Archiver
- Family
- UK Web Archive
- Purpose
- Legal deposit web archiving
Behavior and handling
- Common Use
- preserving UK websites under legal-deposit and web-archiving programs
- Detection Notes
- Detect primarily by `bl.uk_lddc_bot`; related patterns include `bl.uk_lddc_bot/3.4.0; UK Web Archive crawler`; representative HTTP user-agent: `bl.uk_lddc_bot/3.4.0-20220727 (+https://www.bl.uk/legal-deposit/web-archiving)`. User-agent strings can be copied, so corroborate with stronger evidence before granting trust.
- Respects robots.txt
- Yes
- Spoofing Risk
- British Library Legal Deposit Crawler has medium spoofing risk because its user-agent can be copied; use published operator-controlled verification data when available.
- Risk
- Safe
- Recommended Handling
- Do not block
Rules and controls
- Robots.txt Snippet
-
User-agent: bl.uk_lddc_bot Disallow: / - Apache Rule
-
RewriteCond %{HTTP_USER_AGENT} "bl\.uk_lddc_bot" [NC] RewriteRule ^ - [F,L] - Nginx Rule
-
if ($http_user_agent ~* "bl\.uk_lddc_bot") { return 403; }
Relationships
- Operator
- British Library Checked 2026-08-07
Relationships without an Evidence link are normalized from the canonical directory record. They should not be interpreted as independent proof of physical presence or request origin.