diff --git a/pythainlp/corpus/tnc.py b/pythainlp/corpus/tnc.py
index 7a01849a6..21e359b74 100644
--- a/pythainlp/corpus/tnc.py
+++ b/pythainlp/corpus/tnc.py
@@ -1,4 +1,5 @@
-# SPDX-FileCopyrightText: 2016-2026 PyThaiNLP Project.
+# SPDX-FileCopyrightText: 2016-2026 PyThaiNLP Project
+# SPDX-FileType: SOURCE
 # SPDX-License-Identifier: Apache-2.0
 """Thai National Corpus word frequency
 """
diff --git a/pythainlp/tag/_tag_perceptron.py b/pythainlp/tag/_tag_perceptron.py
index d815d64ea..53de2fd46 100644
--- a/pythainlp/tag/_tag_perceptron.py
+++ b/pythainlp/tag/_tag_perceptron.py
@@ -9,6 +9,7 @@
         Wannaphong Phatthiyaphaibun <wannaphong@pythainlp.org> (PyThaiNLP port)
 URL: <https://github.com/sloria/textblob-aptagger>
      <https://nltk.org/>
+
 Copyright 2013 Matthew Honnibal
 NLTK modifications Copyright 2015 The NLTK Project
 PyThaiNLP modifications Copyright 2020 PyThaiNLP Project
diff --git a/pythainlp/tokenize/thai2fit.py b/pythainlp/tokenize/thai2fit.py
index e6f1059f3..fab9dac62 100644
--- a/pythainlp/tokenize/thai2fit.py
+++ b/pythainlp/tokenize/thai2fit.py
@@ -1,4 +1,4 @@
-# SPDX-FileCopyrightText: 2026 PyThaiNLP Project
+# SPDX-FileCopyrightText: 2016-2026 PyThaiNLP Project
 # SPDX-FileType: SOURCE
 # SPDX-License-Identifier: Apache-2.0
 
diff --git a/pythainlp/tokenize/thaisumcut.py b/pythainlp/tokenize/thaisumcut.py
index 9981fda64..f1dc30f37 100644
--- a/pythainlp/tokenize/thaisumcut.py
+++ b/pythainlp/tokenize/thaisumcut.py
@@ -1,5 +1,6 @@
 # SPDX-FileCopyrightText: 2016-2026 PyThaiNLP Project
-# SPDX-FileCopyrightText: Copyright 2020 Nakhun Chumpolsathien
+# SPDX-FileCopyrightText: 2020 Nakhun Chumpolsathien
+# SPDX-FileType: SOURCE
 # SPDX-License-Identifier: Apache-2.0
 """The implementation of sentence segmentator from Nakhun Chumpolsathien, 2020
 original codes are from: https://github.com/nakhunchumpolsathien/ThaiSum
diff --git a/pythainlp/transliterate/thaig2p.py b/pythainlp/transliterate/thaig2p.py
index e3d5c85e5..c86609ad0 100644
--- a/pythainlp/transliterate/thaig2p.py
+++ b/pythainlp/transliterate/thaig2p.py
@@ -22,7 +22,16 @@
 
 
 class ThaiG2P:
-    """Latin transliteration of Thai words, using International Phonetic Alphabet"""
+    """
+    Thai Grapheme-to-Phoneme using PyTorch-based model (v1).
+
+    This is the original Thai G2P model that converts Thai text to
+    International Phonetic Alphabet (IPA) representation using a custom
+    PyTorch neural network architecture.
+
+    For more information, see:
+    https://github.com/wannaphong/thai-g2p
+    """
 
     def __init__(self):
         # get the model, download it if it's not available locally
diff --git a/pythainlp/transliterate/thaig2p_v2.py b/pythainlp/transliterate/thaig2p_v2.py
index aad18c0d4..6ad4fa381 100644
--- a/pythainlp/transliterate/thaig2p_v2.py
+++ b/pythainlp/transliterate/thaig2p_v2.py
@@ -13,7 +13,15 @@
 
 
 class ThaiG2P:
-    """Latin transliteration of Thai words, using International Phonetic Alphabet
+    """
+    Thai Grapheme-to-Phoneme using transformer-based model (v2).
+
+    This version uses the Hugging Face transformers pipeline with the
+    pythainlp/thaig2p-v2.0 model for converting Thai text to International
+    Phonetic Alphabet (IPA) representation.
+
+    For more information, see:
+    https://huggingface.co/pythainlp/thaig2p-v2.0
     """
 
     def __init__(self, device: str = "cpu"):
diff --git a/pythainlp/transliterate/umt5_thaig2p.py b/pythainlp/transliterate/umt5_thaig2p.py
index 4976fe547..57e9c7749 100644
--- a/pythainlp/transliterate/umt5_thaig2p.py
+++ b/pythainlp/transliterate/umt5_thaig2p.py
@@ -13,7 +13,15 @@
 
 
 class Umt5ThaiG2P:
-    """Latin transliteration of Thai words, using International Phonetic Alphabet
+    """
+    Thai Grapheme-to-Phoneme using UMT5 model.
+
+    This version uses the B-K/umt5-thai-g2p-v2-0.5k model based on UMT5
+    (Unified Multilingual T5) for converting Thai text to International
+    Phonetic Alphabet (IPA) representation.
+
+    For more information, see:
+    https://huggingface.co/B-K/umt5-thai-g2p-v2-0.5k
     """
 
     def __init__(self, device: str = "cpu"):