diff --git a/core/src/mast/node/basic_block_node/mod.rs b/core/src/mast/node/basic_block_node/mod.rs
index 66cc659998..e9bec6d0c0 100644
--- a/core/src/mast/node/basic_block_node/mod.rs
+++ b/core/src/mast/node/basic_block_node/mod.rs
@@ -223,7 +223,7 @@ impl fmt::Display for BasicBlockNode {
 // OPERATION OR DECORATOR
 // ================================================================================================
 
-// TODOP: Document
+/// Encodes either an [`Operation`] or a [`Decorator`].
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub enum OperationOrDecorator<'a> {
     Operation(&'a Operation),
diff --git a/core/src/mast/serialization/basic_block_data_builder.rs b/core/src/mast/serialization/basic_block_data_builder.rs
index 886f1a09d9..3ca9ece182 100644
--- a/core/src/mast/serialization/basic_block_data_builder.rs
+++ b/core/src/mast/serialization/basic_block_data_builder.rs
@@ -9,7 +9,7 @@ use crate::{
 
 use super::{decorator::EncodedDecoratorVariant, DataOffset, StringIndex, StringRef};
 
-/// TODOP: Document
+/// Builds the `data` section of a serialized [`crate::mast::MastForest`].
 #[derive(Debug, Default)]
 pub struct BasicBlockDataBuilder {
     data: Vec<u8>,
@@ -25,7 +25,9 @@ impl BasicBlockDataBuilder {
 
 /// Accessors
 impl BasicBlockDataBuilder {
-    pub fn current_data_offset(&self) -> DataOffset {
+    /// Returns the offset in the serialized [`crate::mast::MastForest`] data field that the next
+    /// [`super::MastNodeInfo`] representing a [`BasicBlockNode`] will take.
+    pub fn next_data_offset(&self) -> DataOffset {
         self.data
             .len()
             .try_into()
@@ -35,6 +37,7 @@ impl BasicBlockDataBuilder {
 
 /// Mutators
 impl BasicBlockDataBuilder {
+    /// Encodes a [`BasicBlockNode`] into the serialized [`crate::mast::MastForest`] data field.
     pub fn encode_basic_block(&mut self, basic_block: &BasicBlockNode) {
         // 2nd part of `mast_node_to_info()` (inside the match)
         for op_or_decorator in basic_block.iter() {
@@ -45,6 +48,7 @@ impl BasicBlockDataBuilder {
         }
     }
 
+    /// Returns the serialized [`crate::mast::MastForest`] data field, as well as the string table.
     pub fn into_parts(mut self) -> (Vec<u8>, Vec<StringRef>) {
         let string_table = self.string_table_builder.into_table(&mut self.data);
         (self.data, string_table)
diff --git a/core/src/mast/serialization/decorator.rs b/core/src/mast/serialization/decorator.rs
index 3cb509a039..22024397ca 100644
--- a/core/src/mast/serialization/decorator.rs
+++ b/core/src/mast/serialization/decorator.rs
@@ -3,7 +3,10 @@ use num_traits::{FromPrimitive, ToPrimitive};
 
 use crate::{AdviceInjector, DebugOptions, Decorator};
 
-/// TODOP: Document
+/// Stores all the possible [`Decorator`] variants, without any associated data.
+///
+/// This is effectively equivalent to a set of constants, and designed to convert between variant
+/// discriminant and enum variant conveniently.
 #[derive(FromPrimitive, ToPrimitive)]
 #[repr(u8)]
 pub enum EncodedDecoratorVariant {
diff --git a/core/src/mast/serialization/info.rs b/core/src/mast/serialization/info.rs
index 63ffb216c9..1dec494aac 100644
--- a/core/src/mast/serialization/info.rs
+++ b/core/src/mast/serialization/info.rs
@@ -8,6 +8,15 @@ use super::{basic_block_data_decoder::BasicBlockDataDecoder, DataOffset};
 // MAST NODE INFO
 // ===============================================================================================
 
+/// Represents a serialized [`MastNode`], with some data inlined in its [`MastNodeType`].
+///
+/// In the case of [`crate::mast::BasicBlockNode`], all its operation- and decorator-related data is
+/// stored in the serialized [`MastForest`]'s `data` field at offset represented by the `offset`
+/// field. For all other variants of [`MastNode`], the `offset` field is guaranteed to be 0.
+///
+/// The serialized representation of [`MastNodeInfo`] is guaranteed to be fixed width, so that the
+/// nodes stored in the `nodes` table of the serialzied [`MastForest`] can be accessed quickly by
+/// index.
 #[derive(Debug)]
 pub struct MastNodeInfo {
     ty: MastNodeType,
@@ -125,7 +134,12 @@ const SYSCALL: u8 = 5;
 const DYN: u8 = 6;
 const EXTERNAL: u8 = 7;
 
-/// TODOP: Document the fact that encoded representation is always 8 bytes
+/// Represents the variant of a [`MastNode`], as well as any additional data. For example, for more
+/// efficient decoding, and because of the frequency with which these node types appear, we directly
+/// represent the child indices for `Join`, `Split`, and `Loop`, `Call` and `SysCall` inline.
+///
+/// The serialized representation of the MAST node type is guaranteed to be 8 bytes, so that
+/// [`MastNodeInfo`] (which contains it) can be of fixed width.
 #[derive(Debug)]
 #[repr(u8)]
 pub enum MastNodeType {
@@ -156,6 +170,7 @@ pub enum MastNodeType {
 
 /// Constructors
 impl MastNodeType {
+    /// Constructs a new [`MastNodeType`] from a [`MastNode`].
     pub fn new(mast_node: &MastNode) -> Self {
         use MastNode::*;
 
@@ -199,9 +214,9 @@ impl Serializable for MastNodeType {
             let mut serialized_bytes = self.inline_data_to_bytes();
 
             // Tag is always placed in the first four bytes
-            let tag = self.tag();
-            assert!(tag <= 0b1111);
-            serialized_bytes[0] |= tag << 4;
+            let discriminant = self.discriminant();
+            assert!(discriminant <= 0b1111);
+            serialized_bytes[0] |= discriminant << 4;
 
             serialized_bytes
         };
@@ -212,7 +227,7 @@ impl Serializable for MastNodeType {
 
 /// Serialization helpers
 impl MastNodeType {
-    fn tag(&self) -> u8 {
+    fn discriminant(&self) -> u8 {
         // SAFETY: This is safe because we have given this enum a primitive representation with
         // #[repr(u8)], with the first field of the underlying union-of-structs the discriminant.
         //
@@ -240,7 +255,6 @@ impl MastNodeType {
         }
     }
 
-    // TODOP: Make a diagram of how the bits are split
     fn encode_join_or_split(left_child_id: u32, right_child_id: u32) -> [u8; 8] {
         assert!(left_child_id < 2_u32.pow(30));
         assert!(right_child_id < 2_u32.pow(30));
diff --git a/core/src/mast/serialization/mod.rs b/core/src/mast/serialization/mod.rs
index 0caaf2f96e..b08b58bdda 100644
--- a/core/src/mast/serialization/mod.rs
+++ b/core/src/mast/serialization/mod.rs
@@ -90,7 +90,7 @@ impl Serializable for MastForest {
         // MAST node infos
         for mast_node in &self.nodes {
             let mast_node_info =
-                MastNodeInfo::new(mast_node, basic_block_data_builder.current_data_offset());
+                MastNodeInfo::new(mast_node, basic_block_data_builder.next_data_offset());
 
             if let MastNode::Block(basic_block) = mast_node {
                 basic_block_data_builder.encode_basic_block(basic_block);
diff --git a/core/src/operations/mod.rs b/core/src/operations/mod.rs
index ab201933bd..078abaf72c 100644
--- a/core/src/operations/mod.rs
+++ b/core/src/operations/mod.rs
@@ -451,7 +451,7 @@ pub enum OperationData {
 
 /// Constructors
 impl Operation {
-    // TODOP: document
+    /// Builds an operation from its opcode and inline data (if any).
     pub fn with_opcode_and_data(
         opcode: u8,
         data: OperationData,