@Override
    protected Event doExecuteInternal(final RequestContext requestContext) throws Throwable {
        val request = WebUtils.getHttpServletRequestFromExternalWebflowContext(requestContext);
        val service = WebUtils.getService(requestContext);
        val ticketGrantingTicket = WebUtils.getTicketGrantingTicketId(requestContext);
        FunctionUtils.throwIf(StringUtils.isBlank(ticketGrantingTicket),
            () -> new InvalidTicketException(new AuthenticationException("No ticket-granting ticket could be found in the context"), ticketGrantingTicket));
        val authentication = ticketRegistrySupport.getAuthenticationFrom(ticketGrantingTicket);
        FunctionUtils.throwIfNull(authentication,
            () -> new InvalidTicketException(new AuthenticationException("No authentication found for ticket " + ticketGrantingTicket), ticketGrantingTicket));
        val credentials = casWebflowCredentialProvider.extract(requestContext);
        val authenticationResultBuilder = authenticationSystemSupport.establishAuthenticationContextFromInitial(
            authentication, credentials.toArray(credentials.toArray(Credential.EMPTY_CREDENTIALS_ARRAY)));
        val authenticationResult = FunctionUtils.doUnchecked(() -> authenticationResultBuilder.build(service));
        grantServiceTicket(authenticationResult, service, requestContext);

        if (request.getParameterMap().containsKey(PARAMETER_NAME_IGNORE_WARNING)
            && BooleanUtils.toBoolean(request.getParameter(PARAMETER_NAME_IGNORE_WARNING))) {
            val response = WebUtils.getHttpServletResponseFromExternalWebflowContext(requestContext);
            warnCookieGenerator.removeCookie(response);
        }
        return new Event(this, CasWebflowConstants.STATE_ID_REDIRECT);
    }
Parameter name indicating that warning should be ignored and removed.
support/cas-server-support-actions-core/src/main/java/org/apereo/cas/web/flow/login/ServiceWarningAction.java