jysafe

CN: 最基本的形式： 
 输入上图物质分子式，看着复杂，其实挺简单的，数数各个原子个数，按照顺序堆起来就行了。 
 此外还有计算矩阵、说出事件发生日期的验证码，三者随机出现。
EN: This is a special captcha plugin. 
 It is not verified by math but by chemical formula and Calculation matrix and date of some event.

Traum Captcha

Fetch Designs

This plugin lets you quickly and easily set up sign-up sheets on your WordPress site. Use it for volunteer and time slot sign-ups, personnel and resource coordination, and much more.
The free version of Sign-Up Sheets includes the following features:
<ul>
<li>Administrator can add, edit and clear sign-up spots as needed – add/edit is NEW as of version 2.2.9</li>
<li>Copy a sheet or a task to a new one</li>
<li>Confirmation emails on sign-up</li>
<li>Allow logged-in users to see all the tasks they’ve signed up for on one page using the <a href="https://www.fetchdesigns.com/doc/user_sign_ups-shortcode/" rel="nofollow ugc"><code>[user_sign_ups]</code> shortcode</a>.</li>
<li>No limit on the number of sign-up sheets and sign-up spots</li>
<li>reCAPTCHA (optional) – NEW as of version 2.2</li>
<li>Export sign-up information for a single sheet or all sheets to a CSV</li>
<li>Supports WordPress <a href="//www.fetchdesigns.com/doc/gdpr-sign-up-sheets-wordpress-plugin/)" rel="nofollow ugc">GDPR privacy features for your sign-up sheets</a></li>
<li>Developed with accessibility in mind based on <a href="https://www.w3.org/WAI/standards-guidelines/" rel="nofollow ugc">WCAG Guidelines</a>. If you run into any accessibility issues, <a href="https://www.fetchdesigns.com/contact" rel="nofollow ugc">please report them</a> to help make the plugin more inclusive for all users.</li>
<li>And much more… <a href="https://www.fetchdesigns.com/sign-up-sheets-wordpress-plugin/" rel="nofollow ugc">full list of Sign-up Sheets features</a></li>
</ul>
The Pro version of Sign-Up Sheets includes the following features:
<ul>
<li>Ability to create <a href="https://www.fetchdesigns.com/doc/custom-fields/" rel="nofollow ugc">Custom Task fields and Custom Sign-up form fields</a></li>
<li>Automatically sends reminder emails before an event (optional)</li>
<li>Allows customization of the confirmation and reminder emails per sheet</li>
<li>Assign <a href="https://www.fetchdesigns.com/doc/sheet-categories/" rel="nofollow ugc">categories to sign-up sheets</a> and display a list of current sheets for a specific category.</li>
<li>Logged-in user can edit their own sign-ups</li>
<li>Spot Locking – Locks and holds a spot for 3 minutes when a user accesses the sign-up form (optional)</li>
<li><a href="https://www.fetchdesigns.com/doc/compact-semi-compact-standard-display-modes/" rel="nofollow ugc">Compact and Semi-Compact display modes</a> to condense tasks with a large number of spots into a single line (optional)</li>
<li>Enable sign-up limits per task</li>
<li>And much more… <a href="https://www.fetchdesigns.com/sign-up-sheets-wordpress-plugin/" rel="nofollow ugc">full list of Sign-up Sheets features</a></li>
</ul>
Sign-up Sheets is currently being used by organizations and businesses for non-profit and church volunteer opportunities, schools and PTO/PTA volunteering, club sign-ups, photographer and meeting room timeslot sign-ups, and more. It’s a great alternative to monthly paid services like SignUpGenius and allows you to control your own sign-ups right on your WordPress site.

Sign-up Sheets

An online sign-up sheet manager where your users can sign up for tasks.

Traum Captcha vs Sign-up Sheets