title_body: Is regex available in Sigil clip editor?
upvoted_answer: No, Sigil Clip Editor cannot use replace patterns. The way that Sigil Clips works is you highlight text, and then you apply the Clip.
  
  Your highlighted text will be grouped into:
  
  \1
  
  
  So let's say you highlight:
  
  This is text I |want in italics|.
  
  Clip: &lt;i&gt;\1&lt;/i&gt;
  
  This is text I &lt;i&gt;want in italics&lt;/i&gt;.
  
  Clips are designed more as a one-button-push for redundant stuff (like pasting in template code for a figure with caption, etc. etc.)
  
  For example, mobileread user Tex2002ans created this Sigil Clip for himself:
  
  &lt;div class="chart"&gt;
        &lt;div class="single-chart"&gt;
          &lt;div class="chart-title"&gt;&lt;/div&gt;
  
          &lt;div class="image"&gt;&lt;/div&gt;
  
          &lt;div class="chart-caption"&gt;&lt;/div&gt;
        &lt;/div&gt;
  &lt;/div&gt;
  
  
  and then he can easily just insert the needed info/images.
  
  To do more advanced Search/Replace using Regex, you use Tools > Saved Searches.
  https://www.mobileread.com/forums/showthread.php?p=3808345#post3808345