Respondent Status Codes

When Research Desk redirects a respondent back to your platform, an isc (internal status code) is appended to the callback URL. Use isc to route the respondent to the correct disposition in your panel (complete, term, security, over-quota) and to diagnose why they did not complete. The high-level inbound_code is Rep Data’s internal family for that outcome. You receive the more specific isc on the supplier callback. Research Desk records two related values for every respondent session:

Field	Where it appears	What it means
`inbound_code`	Client redirect URLs (`rdsecured.com/return`), traffic reports, Demand API responses	High-level outcome family (complete, term, security, over-quota, Defender)
`isc`	Supplier callback links, traffic reports	Specific reason within that family

Client survey platforms program client-side inbound_code values on return redirects (1000, 2000, 3000, 4000). Research Desk assigns Desk-side codes (1, 5000, 6000) when it terms or over-quotas a respondent before or during the session. The isc is always returned on the supplier callback link. An Abandon is recorded when no recognized redirect fires. It is not an inbound_code.

Code families

inbound_code	Definition	Assigned by	Supplier redirect
`1`	RDefender Term	Research Desk	Security
`1000`	Complete	Client redirect	Complete
`2000`	Term	Client redirect	Term
`3000`	Client-Side Security Term	Client redirect	Security
`4000`	Client-Side Overquota	Client redirect	OQ
`5000`	Research Desk Term	Research Desk	Term
`6000`	Research Desk Overquota	Research Desk	OQ

isc reference

inbound_code `1` — Research Defender Term

Respondent did not reach the client survey. Redirected to the Security supplier link.

isc	Definition
`2`	Failed on Research Defender SEARCH module
`3`	Failed on Research Defender ACTIVITY module
`4`	Failed on Research Defender REVIEW module
`5`	Failed on Research Defender Complete module
`6`	Failed on Research Defender SEARCH — higher CPI / higher threat
`8`	Failed on Research Defender REVIEW — not contextually correct

inbound_code `1000` — Complete

Respondent reached the client survey. Redirected to the Complete supplier link.

isc	Definition
`1000`	Complete

inbound_code `2000` — Term

Respondent reached the client survey. Redirected to the Term supplier link.

isc	Definition
`2000`	Client-side term (for example, a screening question)

inbound_code `3000` — Client-Side Security Term

Respondent reached the client survey. Redirected to the Security supplier link.

isc	Definition
`3000`	Survey quality term (client side)

inbound_code `4000` — Client-Side Overquota

Respondent reached the client survey. Redirected to the OQ supplier link.

isc	Definition
`4000`	General overquota (client side)

inbound_code `5000` — Research Desk Term

Assigned by Research Desk. Redirected to the Term supplier link.

isc	Definition	Reached client survey
`5001`	Stream closed (Research Desk)	No
`5003`	Qualification mismatch. `TermedQualificationID` is appended on the supplier term link.	No
`5004`	Device compatibility mismatch	No
`5005`	Invalid L2 voter match	No
`5006`	Suspicious device (bot-like detection)	No
`5007`	Sample group exclusion term	No
`5008`	Respondent list mismatch (recontacts / inclusions)	No
`5009`	Qualification verification mismatch	No
`5101`	Attempted bypass of client survey	No
`5102`	Encryption failure (hashing)	Yes
`5103`	Speeder term (under 30 seconds or under 20% of LOI)	Yes
`5104`	Suspicious re-entry attempt	Yes

inbound_code `6000` — Research Desk Overquota

Assigned by Research Desk. Respondent did not reach the client survey. Redirected to the OQ supplier link.

isc	Definition
`6001`	Overall quota achieved (Research Desk)
`6002`	Sub-quota achieved (Research Desk). `TermedQuotaID` is appended on the supplier over-quota link.
`6003`	In-survey maximum exceeded (Research Desk)

SEARCH threat codes (rdThreat)

When isc=2 (SEARCH failure), Research Desk appends an rdThreat value to the supplier redirect. These codes identify the SEARCH signal that terminated the respondent.

rdThreat	Termination reason	Explanation
`02`	Duplicate entrant into survey	The respondent has already attempted this survey, detected via IP address or digital fingerprint.
`03`	Emulator usage	Emulator software can recreate browsers, machines, and operating systems, and spoof other devices. Emulators also allow a respondent to create unique digital fingerprints on a single device.
`04`	VPN usage detected	VPN use alone does not fail SEARCH. Combined with a public proxy and an internet-fraudster flag, VPN usage has a high correlation to fraudulent activity and is terminated.
`05`	TOR network detected	TOR conceals a user’s location. TOR use alone does not indicate fraud, but combined with other flags it contributes to the fraud likelihood. This status means the respondent is currently using TOR or has been linked to a TOR network.
`06`	Public proxy server detected	A proxy is an intermediary between the respondent and a remote connection. This status means the respondent is accessing the survey through a publicly available proxy server, which can be used by multiple respondents at once.
`07`	Web proxy service used	Web proxies are a subset of public proxies that can be accessed via the internet with no software or security.
`08`	Web crawler usage detected	The respondent has been linked to web-crawling activity, which has a high correlation to fraudulent activity, especially in ad-tech.
`09`	Internet fraudster detected	The respondent has been linked to general fraud or abuse on the internet, flagged by one or more third-party vendors that compile digital-fingerprint databases of historically fraudulent respondents.
`10`	Retail and ad-tech fraudster detected	Same as `09`, except the respondent was flagged for fraud or abuse specifically in retail or ad-tech.
`11`	Subnet detected	A subnet recreates an IP address to spoof technologies that look for a direct match, making an IP address appear unique.
`12`	Recent abuse detected	The respondent was recently flagged for fraud or abuse by a fraud-prevention provider (similar to `09`).
`13`	Duplicate survey group detected	Deduplication at the survey group / project level.
`14`	Navigator Webdriver detected	SEARCH detected automation tools (Selenium, Puppeteer, Playwright) in the respondent’s browser or machine.
`15`	Developer tool detected	SEARCH detected a developer-tools window open in the respondent’s browser, often used to manipulate API responses or digital fingerprints.
`16`	WebRTC detected	WebRTC lets SEARCH identify respondents attempting to hide their IP addresses and store the actual IP. This failure is always returned for Threat Potential scores of 31 when 31 is configured as a medium threat level.
`17`	Proxy detected	A T-Mobile proxy was detected on the respondent’s session.
`18`	MaxMind failure	The respondent was flagged as a known internet fraudster.
`19`	Batch fraud entrants	Automatically flags respondents when large groups of survey completes are submitted within unusually short intervals — often seconds or minutes apart.
`20`	ChatGPT / Claude emulators	ChatGPT or Claude emulators and similar automated programs can mimic human behavior. These devices are tracked so survey responses are not automated.
`21`	Previous explicit behavior	Respondents with a history of poor or fraudulent activity in the Defender ecosystem, flagged from prior explicit behavior patterns.
`22`	Obfuscation mechanisms detected	Virtual environments or privacy tools (for example, incognito mode) used to conceal true respondent identity or activity.
`23`	SEARCH locale detected	SEARCH found a mismatch between the session’s language or regional settings and the project’s configured locale.

Redirect link parameters

Research Desk also appends respondent identifiers and context on the callback. See Redirect Link Parameters for RID, PID, TermedQuotaID, TermedQualificationID, stream ID, and survey ID.

Overview

Integration Guide

API Reference (v2)

Code families

isc reference

inbound_code `1` — Research Defender Term

inbound_code `1000` — Complete

inbound_code `2000` — Term

inbound_code `3000` — Client-Side Security Term

inbound_code `4000` — Client-Side Overquota

inbound_code `5000` — Research Desk Term

inbound_code `6000` — Research Desk Overquota

SEARCH threat codes (rdThreat)

Redirect link parameters

​Code families

​isc reference

​inbound_code 1 — Research Defender Term

​inbound_code 1000 — Complete

​inbound_code 2000 — Term

​inbound_code 3000 — Client-Side Security Term

​inbound_code 4000 — Client-Side Overquota

​inbound_code 5000 — Research Desk Term

​inbound_code 6000 — Research Desk Overquota

​SEARCH threat codes (rdThreat)

​Redirect link parameters

​Related pages

Code families

isc reference

inbound_code `1` — Research Defender Term

inbound_code `1000` — Complete

inbound_code `2000` — Term

inbound_code `3000` — Client-Side Security Term

inbound_code `4000` — Client-Side Overquota

inbound_code `5000` — Research Desk Term

inbound_code `6000` — Research Desk Overquota

SEARCH threat codes (rdThreat)

Redirect link parameters

Related pages