TestLink 1.9.20's Test Case Viewer rendered its Requirements block per version panel (gui/templates/dashio/testcases/tcView_viewer.tpl:513-556) when

{if $gui->requirementsEnabled == TRUE &&
  ($gui->view_req_rights == "yes" || $gui->req_tcase_link_management) }

$gui->view_req_rights is the mgt_view_req right (lib/functions/testcase.class.php:7387), so the gate is an OR: a user whose role is "may link requirements to test cases" (req_tcase_link_management) sees the list of linked requirements too, even without mgt_view_req.

Inside the block legacy rendered

• a bold "Requirements" label linking to $hrefReqSpecMgmt (lib/general/frmWorkArea.php?feature=reqSpecMgmt, tpl:31-32),
• a link/unlock icon on the label calling openReqWindow(tcase_id,'a'), gated on the per-version $reqLinkingEnabled (tpl:516-524) and isTheLatest (tpl:530),
• one line per linked requirement, spec_title : doc_id (Version N) : title, each preceded by a clickable icon calling openLinkedReqVersionWindow(req_id, req_version_id, tproject_id) (tpl:544-547) → lib/requirements/reqView.php?showReqSpecTitle=1&requirement_id=…&req_version_id=….

The modern viewer had three defects:

• the coverage gate is now the legacy OR (requirementsEnabled && (mgt_view_req || req_tcase_link_management));
• RC.req_version_id is projected next to the version number and shipped per row;
• new canLinkReqs() — port of $reqLinkingEnabled (tpl:516-524): req_tcase_link_management and mgt_modify_tc (legacy $edit_enabled needs $args_can_do->edit == "yes", which getShowViewerActions() only answers when mgt_modify_tc is granted), and a non-frozen version, and on an executed version testcase_cfg->can_edit_executed;
• new response keys: per-version reqLinkingEnabled and reqSpecMgmtUrl (the modern twin of $hrefReqSpecMgmt).

• canSeeRequirements() — the legacy OR (tcView.html:1230-1240);
• reqSpecMgmtLabelHtml() — the label anchor to reqSpecMgmt.html with tooltip "Open Requirement Specification Management";
• reqOpenIconHtml(rq) — the per-row pencil to reqView.html?showReqSpecTitle=1&id=<req>&req_version_id=<ver>&tproject_id=<prj>, the twin of openLinkedReqVersionWindow(); omitted when the version id is missing (otherwise reqView would silently open the latest version);
• the Link / Unlink Requirements button on the latest version when reqLinkingEnabled, opening the assign dialog (the twin of openReqWindow());
• the toolbar "Assign Requirements" button now uses the same per-version flag instead of grants.req_tcase_link_management alone (it previously ignored frozen versions, executed versions and reqLinkingDisabledAfterExec).

tcview.linkUnlinkReqs, tcview.openLinkedReqTitle, tcview.reqSpecMgmtTitle translated in all 10 locale bundles (en, de, fr, es, it, pt, ro, ru, ja, zh).

• tmp/fixtures_1045.php — three private projects with identical content, differing only in the user's project role: linker (req_tcase_link_management, no mgt_view_req), req-viewer (mgt_view_req), negative control (no requirement right at all).
• tmp/verify_1045.php — 19/19 PASS (API matrix, incl. no new events Error/Warning row).
• Browser (chrome-devtools MCP) — 12/12 PASS: the linker role now sees the section, the label link, the per-row version links and the link/unlock button; the req-viewer sees the section but no link/unlock button; the negative control sees no section at all; admin unaffected; console clean.
• Test suite: section Task — Issue #1045 in tmp/TLU_Test_Cases.md.

Legacy lib/requirements/reqView.php:261-266 self-checks $context->rightsAnd = ["mgt_view_req"], so a user without that right gets a refused requirement window in legacy too (modern: "No permission"). The icon is rendered exactly where legacy rendered it — the target keeps its own rights check.