diff --git a/.vscode/settings.json b/.vscode/settings.json
new file mode 100644
index 00000000..662f9240
--- /dev/null
+++ b/.vscode/settings.json
@@ -0,0 +1,5 @@
+{
+  "conventionalCommits.scopes": [
+    "htmlblock"
+  ]
+}
\ No newline at end of file
diff --git a/README.md b/README.md
index f653183d..431aa437 100644
--- a/README.md
+++ b/README.md
@@ -100,7 +100,64 @@ var md = new Remarkable({
 
   // Highlighter function. Should return escaped HTML,
   // or '' if the source string is not changed
-  highlight: function (/*str, lang*/) { return ''; }
+  highlight: function (/*str, lang*/) { return ''; },
+
+  // Allow / Disallow html tags that are available for parsing HTML
+  htmlAllowedTags: [
+    /^my-.*/,
+    'my-web-component',  // Custom-tag
+
+    'article',
+    'aside',
+    'button',
+    'blockquote',
+    'body',
+    'canvas',
+    'caption',
+    'col',
+    'colgroup',
+    'dd',
+    'div',
+    'dl',
+    'dt',
+    'embed',
+    'fieldset',
+    'figcaption',
+    'figure',
+    'footer',
+    'form',
+    'h1',
+    'h2',
+    'h3',
+    'h4',
+    'h5',
+    'h6',
+    'header',
+    'hgroup',
+    'hr',
+    'iframe',
+    'li',
+    'map',
+    'object',
+    'ol',
+    'output',
+    'p',
+    'pre',
+    'progress',
+    'script',
+    'section',
+    'style',
+    'table',
+    'tbody',
+    'td',
+    'textarea',
+    'tfoot',
+    'th',
+    'tr',
+    'thead',
+    'ul',
+    'video'
+  ]
 });
 
 console.log(md.render('# Remarkable rulezz!'));
diff --git a/lib/rules_block/htmlblock.js b/lib/rules_block/htmlblock.js
index 57f66af4..d5094581 100644
--- a/lib/rules_block/htmlblock.js
+++ b/lib/rules_block/htmlblock.js
@@ -1,10 +1,10 @@
 // HTML block
 
-import block_names from '../common/html_blocks';
+import html_blocks from '../common/html_blocks';
 
 
-var HTML_TAG_OPEN_RE = /^<([a-zA-Z]{1,15})[\s\/>]/;
-var HTML_TAG_CLOSE_RE = /^<\/([a-zA-Z]{1,15})[\s>]/;
+var HTML_TAG_OPEN_RE = /^<([a-zA-Z_-]{1,15})[\s\/>]/;
+var HTML_TAG_CLOSE_RE = /^<\/([a-zA-Z_-]{1,15})[\s>]/;
 
 function isLetter(ch) {
   /*eslint no-bitwise:0*/
@@ -20,9 +20,19 @@ export default function htmlblock(state, startLine, endLine, silent) {
 
   pos += shift;
 
+  let allowedBlocks = html_blocks;
+
   if (!state.options.html) { return false; }
 
-  if (shift > 3 || pos + 2 >= max) { return false; }
+  if (!Array.isArray(allowedBlocks)) {
+    allowedBlocks = Object.keys(allowedBlocks)
+  }
+
+  if (Array.isArray(state.options.htmlAllowedTags)) {
+    allowedBlocks = state.options.htmlAllowedTags;
+  }
+
+  if (shift > 3 + state.blkIndent || pos + 2 >= max) { return false; }
 
   if (state.src.charCodeAt(pos) !== 0x3C/* < */) { return false; }
 
@@ -44,8 +54,19 @@ export default function htmlblock(state, startLine, endLine, silent) {
       match = state.src.slice(pos, max).match(HTML_TAG_OPEN_RE);
       if (!match) { return false; }
     }
+
     // Make sure tag name is valid
-    if (block_names[match[1].toLowerCase()] !== true) { return false; }
+    const tagToCheck = match[1].toLowerCase();
+    if (!allowedBlocks.includes(tagToCheck)) {
+      const regExpressions = allowedBlocks
+        .filter(possibleExpression => typeof possibleExpression !== 'string')
+        .filter(possibleExpression => !!possibleExpression.test);
+
+      if (!regExpressions.some(x => x.test(tagToCheck))) {
+        return false;
+      }
+    }
+
     if (silent) { return true; }
 
   } else {