youtrack-pr-title.user.js

// ==UserScript==
// @name         YouTrack - PR Tile
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  Based on current YouTrack Ticket, copy PR title to the clipboard
// @author       Stepan Riha
// @include      https://spanning.myjetbrains.com/youtrack/issue/*
// @run-at       context-menu
// @grant        GM_setClipboard
// ==/UserScript==

(function() {
    'use strict';
    var info = document.title.match(/(.*) : ([^ ]+)$/);
    if (info) {
        info.shift();
        var title = info.join(' #');
        GM_setClipboard(title, 'text');
        alert(title);
    }
})();