diff --git a/aider/coders/base_coder.py b/aider/coders/base_coder.py
index 902b95033..9e16755e6 100755
--- a/aider/coders/base_coder.py
+++ b/aider/coders/base_coder.py
@@ -1626,10 +1626,6 @@ class Coder:
         mentioned_rel_fnames = set()
         fname_to_rel_fnames = {}
         for rel_fname in addable_rel_fnames:
-            # Skip files that share a basename with files already in chat
-            if os.path.basename(rel_fname) in existing_basenames:
-                continue
-
             normalized_rel_fname = rel_fname.replace("\\", "/")
             normalized_words = set(word.replace("\\", "/") for word in words)
             if normalized_rel_fname in normalized_words:
@@ -1644,6 +1640,10 @@ class Coder:
                 fname_to_rel_fnames[fname].append(rel_fname)
 
         for fname, rel_fnames in fname_to_rel_fnames.items():
+            # If the basename is already in chat, don't add based on a basename mention
+            if fname in existing_basenames:
+                continue
+            # If the basename mention is unique among addable files and present in the text
             if len(rel_fnames) == 1 and fname in words:
                 mentioned_rel_fnames.add(rel_fnames[0])
 
diff --git a/aider/website/docs/troubleshooting/models-and-keys.md b/aider/website/docs/troubleshooting/models-and-keys.md
index 8c6af3543..06fbc9722 100644
--- a/aider/website/docs/troubleshooting/models-and-keys.md
+++ b/aider/website/docs/troubleshooting/models-and-keys.md
@@ -5,7 +5,27 @@ nav_order: 28
 
 # Models and API keys
 
-You need to tell aider which LLM to use and provide an API key.
+Aider needs to know which LLM model you would like to work with and which keys
+to provide when accessing it via API.
+
+## Defaults
+
+If you don't explicitly name a model, aider will try to select a model
+for you to work with.
+
+First, aider will check which 
+[keys you have provided via the environment, config files, or command line arguments](https://aider.chat/docs/config/api-keys.html).
+Based on the available keys, aider will select the best model to use.
+
+If you have not provided any keys, aider will offer to help you connect to 
+[OpenRouter](http://openrouter.ai)
+which provides both free and paid access to most popular LLMs.
+Once connected, aider will select the best model available on OpenRouter
+based on whether you have a free or paid account there.
+
+## Specifying model & key
+
+You can also tell aider which LLM to use and provide an API key.
 The easiest way is to use the `--model` and `--api-key`
 command line arguments, like this:
 
diff --git a/tests/basic/test_coder.py b/tests/basic/test_coder.py
index 8fa5d6426..c58ade1b2 100644
--- a/tests/basic/test_coder.py
+++ b/tests/basic/test_coder.py
@@ -194,8 +194,8 @@ class TestCoder(unittest.TestCase):
             mock.return_value = set([str(fname1), str(fname2), str(fname3)])
             coder.repo.get_tracked_files = mock
 
-            # Check that file mentions skip files with duplicate basenames
-            mentioned = coder.get_file_mentions(f"Check {fname2} and {fname3}")
+            # Check that file mentions of a pure basename skips files with duplicate basenames
+            mentioned = coder.get_file_mentions(f"Check {fname2.name} and {fname3}")
             self.assertEqual(mentioned, {str(fname3)})
 
             # Add a read-only file with same basename
@@ -366,6 +366,45 @@ class TestCoder(unittest.TestCase):
                         f"Failed to extract mentions from: {content}",
                     )
 
+    def test_get_file_mentions_multiline_backticks(self):
+        with GitTemporaryDirectory():
+            io = InputOutput(pretty=False, yes=True)
+            coder = Coder.create(self.GPT35, None, io)
+
+            # Create test files
+            test_files = [
+                "swebench/harness/test_spec/python.py",
+                "swebench/harness/test_spec/javascript.py",
+            ]
+            for fname in test_files:
+                fpath = Path(fname)
+                fpath.parent.mkdir(parents=True, exist_ok=True)
+                fpath.touch()
+
+            # Mock get_addable_relative_files to return our test files
+            coder.get_addable_relative_files = MagicMock(return_value=set(test_files))
+
+            # Input text with multiline backticked filenames
+            content = """
+Could you please **add the following files to the chat**?
+
+1.  `swebench/harness/test_spec/python.py`
+2.  `swebench/harness/test_spec/javascript.py`
+
+Once I have these, I can show you precisely how to do the thing.
+"""
+            expected_mentions = {
+                "swebench/harness/test_spec/python.py",
+                "swebench/harness/test_spec/javascript.py",
+            }
+
+            mentioned_files = coder.get_file_mentions(content)
+            self.assertEqual(
+                mentioned_files,
+                expected_mentions,
+                f"Failed to extract mentions from multiline backticked content: {content}",
+            )
+
     def test_get_file_mentions_path_formats(self):
         with GitTemporaryDirectory():
             io = InputOutput(pretty=False, yes=True)