diff --git a/README.md b/README.md
index bf07d7f..2f123f1 100644
--- a/README.md
+++ b/README.md
@@ -49,6 +49,12 @@ postcss([bike()]).process(css).then((res) => console.log(output.css));
     }
   }
 
+  @mod theme[foo|bar] {
+    @elem header {
+      position: absolute;
+    }
+  }
+  
   @elem header {
     flex: 0 0 50px;
     background-color: #fff;
@@ -90,6 +96,10 @@ Transformed to:
   background-color: #1b1b1b;
   color: #fff;
 }
+.example_theme_foo .example__header,
+.example_theme_bar .example__header {
+  position: absolute;
+}
 .example__header {
   flex: 0 0 50px;
   background-color: #fff;
@@ -134,10 +144,11 @@ Allows to set custom name for modifier `@rule`.
 ### `modifierRegExp`
 
 type: `RegExp`  
-default: `{modifierRegExp: /(\w+)\[(\w+)\]/}`
+default: `{modifierRegExp: /(\w+)\[(\w+)| \]/}`
 
 Allows to set custom regular expressions for modifier params. Where `$1` is Modifier Name and `$2` is Modifier Value. For 
 changing Modifier Value Separator, change default separator `\[$2\]`, which goes before and after `$2` (only this `[ ]` symbols).
+Multiple values (used as 'OR') can be separated with a vertical pipe (`|`).
 
 
 ### License [MIT](LICENSE)
diff --git a/src/bem.js b/src/bem.js
index b51e28b..fccd4b1 100644
--- a/src/bem.js
+++ b/src/bem.js
@@ -5,22 +5,29 @@ export const BEM = (block) => (elem, mods) => {
     return base;
   }
 
+  // Handle multiple bases e.g. comma-separated elements.
+  let bases = [base];
+
   if (typeof elem === 'object') {
     mods = elem;
     elem = '';
   }
 
   if (elem !== '') {
-    base = `.${block}__${elem}`;
+    bases = elem.split(',').map(elem => {
+      return `.${block}__${elem.trim()}`;
+    });
   }
 
-  return (mods ? Object.entries(mods).reduce((target, [key, value]) => {
-    if (!value) {
-      return target;
-    }
+  return bases.map(base => {
+    return mods ? Object.entries(mods).reduce((target, [key, value]) => {
+      if (!value) {
+        return target;
+      }
 
-    target += `${value === true ? (`${base}_${key}`) : (`${base}_${key}_${value}`)}`;
+      target += `${value === true ? (`${base}_${key}`) : (`${base}_${key}_${value}`)}`;
 
-    return target;
-  }, '') : base);
+      return target;
+    }, '') : base;
+  }).join(', ');
 };
diff --git a/src/index.js b/src/index.js
index aab867b..b933ad4 100644
--- a/src/index.js
+++ b/src/index.js
@@ -5,7 +5,7 @@ const DEFAULT_OPTIONS = {
   component: 'component',
   element: 'elem',
   modifier: 'mod',
-  modifierRegExp: /([\w\-]+)(?:\[([\w\-]+)\])?/
+  modifierRegExp: /([\w\-]+)(?:\[([\w\-| ]+)\])?/
 };
 
 export default postcss.plugin('postcss-bike', (options = DEFAULT_OPTIONS) => {
@@ -21,37 +21,46 @@ export default postcss.plugin('postcss-bike', (options = DEFAULT_OPTIONS) => {
         node.metadata = { bem: BEM(node.params), type: options.component };
       }
 
-      let selector = '';
-
-      switch (node.metadata.type) {
-        case options.component:
-          selector = node.metadata.bem();
-          break;
-        case options.modifier:
-          let [, modName, modVal = true] = node.metadata.name.match(options.modifierRegExp);
-
-          node.metadata.mods = { [modName]: modVal };
-
-          if (node.parent.metadata.type === options.element) {
-            selector = node.metadata.bem(node.parent.metadata.name, { [modName]: modVal });
-          } else if (node.parent.metadata.type === options.modifier) {
-            selector = node.metadata.bem({ ...node.parent.metadata.mods, [modName]: modVal });
-          } else {
-            selector = node.metadata.bem({ [modName]: modVal });
-          }
-          break;
-        case options.element:
-          if (node.parent.metadata.type === options.modifier) {
-            selector = [node.parent.selector, node.metadata.bem(node.metadata.name)].join(' ');
-          } else {
-            selector = node.metadata.bem(node.metadata.name);
-          }
-          break;
-      }
+      let selectors = [];
+
+      node.metadata.names = node.metadata.name ? node.metadata.name.split(',').map(val => val.trim()) : [''];
+      node.metadata.names.forEach(metaName => {
+        switch (node.metadata.type) {
+          case options.component:
+            selectors.push(node.metadata.bem());
+            break;
+          case options.modifier:
+            let [, modName, modVals = true] = metaName.match(options.modifierRegExp);
+
+            // Handle possible multiple comma-delimited modifier values.
+            modVals = typeof modVals === 'string' ? modVals.split('|').map(val => val.trim()) : [modVals];
+            modVals.forEach(modVal => {
+              node.metadata.mods = { [modName]: modVal };
+
+              if (node.parent.metadata.type === options.element) {
+                selectors.push(node.metadata.bem(node.parent.metadata.name, { [modName]: modVal }));
+              } else if (node.parent.metadata.type === options.modifier) {
+                selectors.push(node.metadata.bem({ ...node.parent.metadata.mods, [modName]: modVal }));
+              } else {
+                selectors.push(node.metadata.bem({ [modName]: modVal }));
+              }
+            });
+            break;
+          case options.element:
+            if (node.parent.metadata.type === options.modifier) {
+              node.parent.selectors.forEach(parentSelector => {
+                selectors.push([parentSelector, node.metadata.bem(metaName)].join(' '));
+              });
+            } else {
+              selectors.push(node.metadata.bem(metaName));
+            }
+            break;
+        }
+      });
 
       const rule = postcss.rule({
         raws: { semicolon: true },
-        selector: selector,
+        selectors: selectors,
         source: node.source,
         metadata: node.metadata
       });