When doing something like <!--video-id:abcabc-->

{% assign video-id = collection.description | split: 'video-id:' | last | split: '-->' | first %}

When you need multiple and dont know how many,

Example images for a slider:

{% assign inaction-images = collection.description | split: '<!--endinaction-->' | first | split: '<img' %}

{% for image in inaction-images %}
  {% if forloop.first == true %}
    {% comment %}do nothing because this is text/html before the img tag{% endcomment %}
  {% else %}
    {% assign src = image | split: ' src="' | last | split:'"' | first %}
    <a href="javascript:;" class="js-in-action-image" data-sort="0" data-image="{{ src }}" data-zoom-image="{{ src }}">
      <img src="{{ src }}" />
    </a>
   {% endif %}
{% endfor %}

Example, handles grabbed from a list of comments <!--add-on:test-chocolate--><!--add-on:test-liquor-->

{% if product.description contains 'add-on:' %}

  {% assign add-on-list = product.description | split: 'add-on:' %}

  <div class="add-ons">

    {% for add-on in add-on-list %}
      {% unless forloop.first %}
        {% assign handle = add-on | split: ':' | last | split: '-->' | first %}

        <div class="add-on-item">
          <p>{{ all_products[handle].title }}</p>
          <img src="{{ all_products[handle].featured_image | img_url: '200x' }}" alt="">
        </div>

      {% endunless %}
    {% endfor %}

  </div>

{% endif %}