diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index 04ab38e18..afca9eb1b 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -287,9 +287,9 @@ The types are defined topologically to aid in facilitating an executable version
     # Epoch number
     'epoch': 'uint64',
     # Root of the previous crosslink
-    'previous_crosslink_root': 'bytes32',
+    'parent_crosslink_root': 'bytes32',
     # Root of the crosslinked shard data since the previous crosslink
-    'crosslink_data_root': 'bytes32',
+    'data_root': 'bytes32',
 }
 ```
 
@@ -369,7 +369,7 @@ The types are defined topologically to aid in facilitating an executable version
 ```python
 {
     'slot': 'uint64',
-    'previous_block_root': 'bytes32',
+    'parent_block_root': 'bytes32',
     'state_root': 'bytes32',
     'block_body_root': 'bytes32',
     'signature': 'bytes96',
@@ -536,7 +536,7 @@ The types are defined topologically to aid in facilitating an executable version
 {
     # Header
     'slot': 'uint64',
-    'previous_block_root': 'bytes32',
+    'parent_block_root': 'bytes32',
     'state_root': 'bytes32',
     'body': BeaconBlockBody,
     'signature': 'bytes96',
@@ -1306,12 +1306,12 @@ def get_attesting_balance(state: BeaconState, attestations: List[PendingAttestat
 def get_winning_crosslink_and_attesting_indices(state: BeaconState, epoch: Epoch, shard: Shard) -> Tuple[Crosslink, List[ValidatorIndex]]:
     attestations = [a for a in get_matching_source_attestations(state, epoch) if a.data.crosslink.shard == shard]
     crosslinks = list(filter(
-        lambda c: hash_tree_root(state.current_crosslinks[shard]) in (c.previous_crosslink_root, hash_tree_root(c)),
+        lambda c: hash_tree_root(state.current_crosslinks[shard]) in (c.parent_crosslink_root, hash_tree_root(c)),
         [a.data.crosslink for a in attestations]
     ))
     # Winning crosslink has the crosslink data root with the most balance voting for it (ties broken lexicographically)
     winning_crosslink = max(crosslinks, key=lambda c: (
-        get_attesting_balance(state, [a for a in attestations if a.data.crosslink == c]), c.crosslink_data_root
+        get_attesting_balance(state, [a for a in attestations if a.data.crosslink == c]), c.data_root
     ), default=Crosslink())
     winning_attestations = [a for a in attestations if a.data.crosslink == winning_crosslink]
     return winning_crosslink, get_unslashed_attesting_indices(state, winning_attestations)
@@ -1586,11 +1586,11 @@ def process_block_header(state: BeaconState, block: BeaconBlock) -> None:
     # Verify that the slots match
     assert block.slot == state.slot
     # Verify that the parent matches
-    assert block.previous_block_root == signing_root(state.latest_block_header)
+    assert block.parent_block_root == signing_root(state.latest_block_header)
     # Save current block as the new latest block
     state.latest_block_header = BeaconBlockHeader(
         slot=block.slot,
-        previous_block_root=block.previous_block_root,
+        parent_block_root=block.parent_block_root,
         block_body_root=hash_tree_root(block.body),
     )
     # Verify proposer is not slashed
@@ -1707,18 +1707,18 @@ def process_attestation(state: BeaconState, attestation: Attestation) -> None:
     assert data.target_epoch in (get_previous_epoch(state), get_current_epoch(state))
     if data.target_epoch == get_current_epoch(state):
         ffg_data = (state.current_justified_epoch, state.current_justified_root, get_current_epoch(state))
-        previous_crosslink = state.current_crosslinks[data.crosslink.shard]
+        parent_crosslink = state.current_crosslinks[data.crosslink.shard]
         state.current_epoch_attestations.append(pending_attestation)
     else:
         ffg_data = (state.previous_justified_epoch, state.previous_justified_root, get_previous_epoch(state))
-        previous_crosslink = state.previous_crosslinks[data.crosslink.shard]
+        parent_crosslink = state.previous_crosslinks[data.crosslink.shard]
         state.previous_epoch_attestations.append(pending_attestation)
 
     # Check FFG data, crosslink data, and signature
     assert ffg_data == (data.source_epoch, data.source_root, data.target_epoch)
-    assert data.crosslink.epoch == min(data.target_epoch, previous_crosslink.epoch + MAX_EPOCHS_PER_CROSSLINK)
-    assert data.crosslink.previous_crosslink_root == hash_tree_root(previous_crosslink)
-    assert data.crosslink.crosslink_data_root == ZERO_HASH  # [to be removed in phase 1]
+    assert data.crosslink.epoch == min(data.target_epoch, parent_crosslink.epoch + MAX_EPOCHS_PER_CROSSLINK)
+    assert data.crosslink.parent_crosslink_root == hash_tree_root(parent_crosslink)
+    assert data.crosslink.data_root == ZERO_HASH  # [to be removed in phase 1]
     assert verify_indexed_attestation(state, convert_to_indexed(state, attestation))
 ```
 
diff --git a/specs/core/0_fork-choice.md b/specs/core/0_fork-choice.md
index 549e9e207..891120de8 100644
--- a/specs/core/0_fork-choice.md
+++ b/specs/core/0_fork-choice.md
@@ -38,7 +38,7 @@ All terminology, constants, functions, and protocol mechanics defined in the [Ph
 
 Processing the beacon chain is similar to processing the Ethereum 1.0 chain. Clients download and process blocks and maintain a view of what is the current "canonical chain", terminating at the current "head". For a beacon block, `block`, to be processed by a node, the following conditions must be met:
 
-* The parent block with root `block.previous_block_root` has been processed and accepted.
+* The parent block with root `block.parent_block_root` has been processed and accepted.
 * An Ethereum 1.0 block pointed to by the `state.latest_eth1_data.block_hash` has been processed and accepted.
 * The node's Unix time is greater than or equal to `state.genesis_time + block.slot * SECONDS_PER_SLOT`.
 
diff --git a/specs/core/1_custody-game.md b/specs/core/1_custody-game.md
index e259b82a5..a030c577b 100644
--- a/specs/core/1_custody-game.md
+++ b/specs/core/1_custody-game.md
@@ -147,7 +147,7 @@ This document details the beacon chain additions and changes in Phase 1 of Ether
     'challenger_index': ValidatorIndex,
     'responder_index': ValidatorIndex,
     'deadline': Epoch,
-    'crosslink_data_root': Hash,
+    'data_root': Hash,
     'depth': 'uint64',
     'chunk_index': 'uint64',
 }
@@ -161,7 +161,7 @@ This document details the beacon chain additions and changes in Phase 1 of Ether
     'challenger_index': ValidatorIndex,
     'responder_index': ValidatorIndex,
     'deadline': Epoch,
-    'crosslink_data_root': Hash,
+    'data_root': Hash,
     'chunk_count': 'uint64',
     'chunk_bits_merkle_root': Hash,
     'responder_key': BLSSignature,
@@ -474,7 +474,7 @@ def process_chunk_challenge(state: BeaconState,
     # Verify the challenge is not a duplicate
     for record in state.custody_chunk_challenge_records:
         assert (
-            record.crosslink_data_root != challenge.attestation.data.crosslink.crosslink_data_root or
+            record.data_root != challenge.attestation.data.crosslink.data_root or
             record.chunk_index != challenge.chunk_index
         )
     # Verify depth
@@ -486,7 +486,7 @@ def process_chunk_challenge(state: BeaconState,
         challenger_index=get_beacon_proposer_index(state),
         responder_index=challenge.responder_index
         deadline=get_current_epoch(state) + CUSTODY_RESPONSE_DEADLINE,
-        crosslink_data_root=challenge.attestation.data.crosslink.crosslink_data_root,
+        data_root=challenge.attestation.data.crosslink.data_root,
         depth=depth,
         chunk_index=challenge.chunk_index,
     )
@@ -564,7 +564,7 @@ def process_bit_challenge(state: BeaconState,
         challenger_index=challenge.challenger_index,
         responder_index=challenge.responder_index,
         deadline=get_current_epoch(state) + CUSTODY_RESPONSE_DEADLINE,
-        crosslink_data_root=challenge.attestation.data.crosslink.crosslink_data_root,
+        data_root=challenge.attestation.data.crosslink.data_root,
         chunk_count=chunk_count,
         chunk_bits_merkle_root=merkle_root(pad_to_power_of_2((challenge.chunk_bits))),
         responder_key=challenge.responder_key,
@@ -610,7 +610,7 @@ def process_chunk_challenge_response(state: BeaconState,
         branch=response.data_branch,
         depth=challenge.depth,
         index=response.chunk_index,
-        root=challenge.crosslink_data_root,
+        root=challenge.data_root,
     )
     # Clear the challenge
     records = state.custody_chunk_challenge_records
@@ -632,7 +632,7 @@ def process_bit_challenge_response(state: BeaconState,
         branch=response.data_branch,
         depth=math.log2(next_power_of_two(challenge.chunk_count)),
         index=response.chunk_index,
-        root=challenge.crosslink_data_root,
+        root=challenge.data_root,
     )
     # Verify the chunk bit leaf matches the challenge data
     assert verify_merkle_branch(
diff --git a/specs/core/1_shard-data-chains.md b/specs/core/1_shard-data-chains.md
index 9fbc69692..316bd0068 100644
--- a/specs/core/1_shard-data-chains.md
+++ b/specs/core/1_shard-data-chains.md
@@ -78,7 +78,7 @@ This document describes the shard data layer and the shard fork choice rule in P
     'slot': Slot,
     'shard': Shard,
     'beacon_chain_root': Hash,
-    'previous_block_root': Hash,
+    'parent_block_root': Hash,
     'data': ShardBlockBody,
     'state_root': Hash,
     'attestations': [ShardAttestation],
@@ -93,7 +93,7 @@ This document describes the shard data layer and the shard fork choice rule in P
     'slot': Slot,
     'shard': Shard,
     'beacon_chain_root': Hash,
-    'previous_block_root': Hash,
+    'parent_block_root': Hash,
     'body_root': Hash,
     'state_root': Hash,
     'attestations': [ShardAttestation],
@@ -201,7 +201,7 @@ def get_shard_header(block: ShardBlock) -> ShardBlockHeader:
         slot: block.slot,
         shard: block.shard,
         beacon_chain_root: block.beacon_chain_root,
-        previous_block_root: block.previous_block_root,
+        parent_block_root: block.parent_block_root,
         body_root: hash_tree_root(block.body),
         state_root: block.state_root,
         attestations: block.attestations,
@@ -296,11 +296,11 @@ def is_valid_shard_block(beacon_blocks: List[BeaconBlock],
 
     # Check parent block
     if block.slot == PHASE_1_GENESIS_SLOT:
-        assert candidate.previous_block_root == ZERO_HASH
+        assert candidate.parent_block_root == ZERO_HASH
     else:
         parent_block = next(
             block for block in valid_shard_blocks if
-            signing_root(block) == candidate.previous_block_root
+            signing_root(block) == candidate.parent_block_root
         , None)
         assert parent_block != None
         assert parent_block.shard == block.shard
@@ -378,11 +378,11 @@ def is_valid_beacon_attestation(shard: Shard,
 
     # Check previous attestation
     if candidate.data.previous_crosslink.epoch <= PHASE_1_GENESIS_EPOCH:
-        assert candidate.data.previous_crosslink.crosslink_data_root == ZERO_HASH
+        assert candidate.data.previous_crosslink.data_root == ZERO_HASH
     else:
         previous_attestation = next(
             attestation for attestation in valid_attestations if
-            attestation.data.crosslink.crosslink_data_root == candidate.data.previous_crosslink.crosslink_data_root
+            attestation.data.crosslink.data_root == candidate.data.previous_crosslink.data_root
         , None)
         assert previous_attestation != None
         assert candidate.data.previous_attestation.epoch < slot_to_epoch(candidate.data.slot)
@@ -393,7 +393,7 @@ def is_valid_beacon_attestation(shard: Shard,
     blocks = []
     for slot in range(start_epoch * SLOTS_PER_EPOCH, end_epoch * SLOTS_PER_EPOCH):
         blocks.append(shard_blocks[slot])
-    assert candidate.data.crosslink.crosslink_data_root == compute_crosslink_data_root(blocks)
+    assert candidate.data.crosslink.data_root == compute_crosslink_data_root(blocks)
 
     return True
 ```
diff --git a/specs/validator/0_beacon-chain-validator.md b/specs/validator/0_beacon-chain-validator.md
index cfe6a8f1f..dae9ac85f 100644
--- a/specs/validator/0_beacon-chain-validator.md
+++ b/specs/validator/0_beacon-chain-validator.md
@@ -152,7 +152,7 @@ Set `block.slot = slot` where `slot` is the current slot at which the validator
 
 ##### Parent root
 
-Set `block.previous_block_root = signing_root(parent)`.
+Set `block.parent_block_root = signing_root(parent)`.
 
 ##### State root
 
@@ -275,11 +275,11 @@ Set `attestation_data.crosslink.shard = shard` where `shard` is the shard associ
 
 ##### Previous crosslink root
 
-Set `attestation_data.previous_crosslink_root = hash_tree_root(head_state.current_crosslinks[shard])`.
+Set `attestation_data.parent_crosslink_root = hash_tree_root(head_state.current_crosslinks[shard])`.
 
 ##### Crosslink data root
 
-Set `attestation_data.crosslink.crosslink_data_root = ZERO_HASH`.
+Set `attestation_data.crosslink.data_root = ZERO_HASH`.
 
 *Note*: This is a stub for Phase 0.
 
diff --git a/test_libs/pyspec/tests/block_processing/test_process_attestation.py b/test_libs/pyspec/tests/block_processing/test_process_attestation.py
index 24cafc275..fcbc68fe9 100644
--- a/test_libs/pyspec/tests/block_processing/test_process_attestation.py
+++ b/test_libs/pyspec/tests/block_processing/test_process_attestation.py
@@ -113,7 +113,7 @@ def test_non_zero_crosslink_data_root(state):
     attestation = get_valid_attestation(state)
     state.slot += spec.MIN_ATTESTATION_INCLUSION_DELAY
 
-    attestation.data.crosslink.crosslink_data_root = b'\x42' * 32
+    attestation.data.crosslink.data_root = b'\x42' * 32
 
     pre_state, post_state = run_attestation_processing(state, attestation, False)
 
diff --git a/test_libs/pyspec/tests/block_processing/test_process_block_header.py b/test_libs/pyspec/tests/block_processing/test_process_block_header.py
index b35b0a9c1..e4fa516b1 100644
--- a/test_libs/pyspec/tests/block_processing/test_process_block_header.py
+++ b/test_libs/pyspec/tests/block_processing/test_process_block_header.py
@@ -53,9 +53,9 @@ def test_invalid_slot(state):
     return pre_state, block, None
 
 
-def test_invalid_previous_block_root(state):
+def test_invalid_parent_block_root(state):
     block = build_empty_block_for_next_slot(state)
-    block.previous_block_root = b'\12' * 32  # invalid prev root
+    block.parent_block_root = b'\12' * 32  # invalid prev root
 
     pre_state, post_state = run_block_header_processing(state, block, valid=False)
     return pre_state, block, None
diff --git a/test_libs/pyspec/tests/helpers.py b/test_libs/pyspec/tests/helpers.py
index 1ea299453..e7ee826db 100644
--- a/test_libs/pyspec/tests/helpers.py
+++ b/test_libs/pyspec/tests/helpers.py
@@ -128,7 +128,7 @@ def build_empty_block_for_next_slot(state):
     previous_block_header = deepcopy(state.latest_block_header)
     if previous_block_header.state_root == spec.ZERO_HASH:
         previous_block_header.state_root = state.hash_tree_root()
-    empty_block.previous_block_root = signing_root(previous_block_header)
+    empty_block.parent_block_root = signing_root(previous_block_header)
     return empty_block
 
 
@@ -155,7 +155,7 @@ def build_attestation_data(state, slot, shard):
     assert state.slot >= slot
 
     if slot == state.slot:
-        block_root = build_empty_block_for_next_slot(state).previous_block_root
+        block_root = build_empty_block_for_next_slot(state).parent_block_root
     else:
         block_root = get_block_root_at_slot(state, slot)
 
@@ -184,8 +184,8 @@ def build_attestation_data(state, slot, shard):
         crosslink=Crosslink(
             shard=shard,
             epoch=min(slot_to_epoch(slot), crosslinks[shard].epoch + MAX_EPOCHS_PER_CROSSLINK),
-            crosslink_data_root=spec.ZERO_HASH,
-            previous_crosslink_root=hash_tree_root(crosslinks[shard]),
+            data_root=spec.ZERO_HASH,
+            parent_crosslink_root=hash_tree_root(crosslinks[shard]),
         ),
     )
 
@@ -240,12 +240,12 @@ def get_valid_proposer_slashing(state):
 
     header_1 = BeaconBlockHeader(
         slot=slot,
-        previous_block_root=ZERO_HASH,
+        parent_block_root=ZERO_HASH,
         state_root=ZERO_HASH,
         block_body_root=ZERO_HASH,
     )
     header_2 = deepcopy(header_1)
-    header_2.previous_block_root = b'\x02' * 32
+    header_2.parent_block_root = b'\x02' * 32
     header_2.slot = slot + 1
 
     domain = get_domain(
diff --git a/test_libs/pyspec/tests/test_sanity.py b/test_libs/pyspec/tests/test_sanity.py
index 1b4d20f4c..83ba9cc11 100644
--- a/test_libs/pyspec/tests/test_sanity.py
+++ b/test_libs/pyspec/tests/test_sanity.py
@@ -68,7 +68,7 @@ def test_empty_block_transition(state):
     state_transition(test_state, block)
 
     assert len(test_state.eth1_data_votes) == len(state.eth1_data_votes) + 1
-    assert get_block_root_at_slot(test_state, state.slot) == block.previous_block_root
+    assert get_block_root_at_slot(test_state, state.slot) == block.parent_block_root
 
     return state, [block], test_state
 
@@ -82,7 +82,7 @@ def test_skipped_slots(state):
 
     assert test_state.slot == block.slot
     for slot in range(state.slot, test_state.slot):
-        assert get_block_root_at_slot(test_state, slot) == block.previous_block_root
+        assert get_block_root_at_slot(test_state, slot) == block.parent_block_root
 
     return state, [block], test_state
 
@@ -96,7 +96,7 @@ def test_empty_epoch_transition(state):
 
     assert test_state.slot == block.slot
     for slot in range(state.slot, test_state.slot):
-        assert get_block_root_at_slot(test_state, slot) == block.previous_block_root
+        assert get_block_root_at_slot(test_state, slot) == block.parent_block_root
 
     return state, [block], test_state