diff --git a/boards/index.rst b/boards/index.rst
index f159f80b80e..0643a355e59 100644
--- a/boards/index.rst
+++ b/boards/index.rst
@@ -13,8 +13,20 @@ Shields are hardware add-ons that can be stacked on top of a board to add extra
 functionality. They are listed separately from boards, towards :ref:`the end of
 this page <boards-shields>`.
 
-Use the interactive search form below to quickly navigate through the list of
-supported boards.
+.. admonition:: Search Tips
+   :class: dropdown
+
+   * Use the form below to filter the list of supported boards. If a field is left empty, it will
+     not be used in the filtering process.
+
+   * A board must meet **all** criteria selected across different fields. For example, if you select
+     both a vendor and an architecture, only boards that match both will be displayed. Within a
+     single field, selecting multiple options (such as two architectures) will show boards matching
+     **either** option.
+
+   * Can't find your exact board? Don't worry! If a similar board with the same or a closely related
+     MCU exists, you can use it as a :ref:`starting point <create-your-board-directory>` for adding
+     support for your own board.
 
 .. toctree::
    :maxdepth: 2
diff --git a/doc/_extensions/zephyr/domain/static/js/board-catalog.js b/doc/_extensions/zephyr/domain/static/js/board-catalog.js
index 2346156cdee..6ac7ae946b8 100644
--- a/doc/_extensions/zephyr/domain/static/js/board-catalog.js
+++ b/doc/_extensions/zephyr/domain/static/js/board-catalog.js
@@ -76,7 +76,7 @@ function fillSocSocSelect(families, series = undefined, selectOnFill = false) {
 
   families = families?.length ? families : Object.keys(socs_data);
   series = series?.length ? series : families.flatMap(f => Object.keys(socs_data[f]));
-  matchingSocs = families.flatMap(f => series.flatMap(s => socs_data[f][s] || []));
+  matchingSocs = [...new Set(families.flatMap(f => series.flatMap(s => socs_data[f][s] || [])))];
 
   socSocSelect.innerHTML = "";
   matchingSocs.sort().forEach((soc) => {