diff --git a/specs/core/0_beacon-chain.md b/specs/core/0_beacon-chain.md
index 47dd765af..7eb9752bb 100644
--- a/specs/core/0_beacon-chain.md
+++ b/specs/core/0_beacon-chain.md
@@ -335,22 +335,19 @@ The types are defined topologically to aid in facilitating an executable version
 
 ```python
 {
-    # Slot number
+    # LMD GHOST vote
     'slot': 'uint64',
-    # Shard number
-    'shard': 'uint64',
-    # Root of the signed beacon block
     'beacon_block_root': 'bytes32',
-    # Root of the ancestor at the epoch boundary
-    'epoch_boundary_root': 'bytes32',
-    # Data from the shard since the last attestation
+
+    # FFG vote
+    'source_epoch': 'uint64',
+    'source_root': 'bytes32',
+    'target_root': 'bytes32',
+
+    # Crosslink vote
+    'shard': 'uint64',
+    'previous_crosslink': Crosslink,
     'crosslink_data_root': 'bytes32',
-    # Last crosslink
-    'latest_crosslink': Crosslink,
-    # Last justified epoch in the beacon state
-    'justified_epoch': 'uint64',
-    # Hash of the last justified beacon block
-    'justified_block_root': 'bytes32',
 }
 ```
 
@@ -612,9 +609,9 @@ The types are defined topologically to aid in facilitating an executable version
     'previous_epoch_attestations': [PendingAttestation],
     'current_epoch_attestations': [PendingAttestation],
     'previous_justified_epoch': 'uint64',
-    'justified_epoch': 'uint64',
+    'current_justified_epoch': 'uint64',
     'previous_justified_root': 'bytes32',
-    'justified_root': 'bytes32',
+    'current_justified_root': 'bytes32',
     'justification_bitfield': 'uint64',
     'finalized_epoch': 'uint64',
 
@@ -1225,8 +1222,8 @@ def is_surround_vote(attestation_data_1: AttestationData,
     """
     Check if ``attestation_data_1`` surrounds ``attestation_data_2``.
     """
-    source_epoch_1 = attestation_data_1.justified_epoch
-    source_epoch_2 = attestation_data_2.justified_epoch
+    source_epoch_1 = attestation_data_1.source_epoch
+    source_epoch_2 = attestation_data_2.source_epoch
     target_epoch_1 = slot_to_epoch(attestation_data_1.slot)
     target_epoch_2 = slot_to_epoch(attestation_data_2.slot)
 
@@ -1547,9 +1544,9 @@ def get_genesis_beacon_state(genesis_validator_deposits: List[Deposit],
         previous_epoch_attestations=[],
         current_epoch_attestations=[],
         previous_justified_epoch=GENESIS_EPOCH,
-        justified_epoch=GENESIS_EPOCH,
+        current_justified_epoch=GENESIS_EPOCH,
         previous_justified_root=ZERO_HASH,
-        justified_root=ZERO_HASH,
+        current_justified_root=ZERO_HASH,
         justification_bitfield=0,
         finalized_epoch=GENESIS_EPOCH,
 
@@ -1733,7 +1730,7 @@ def get_attesting_balance(state: BeaconState, attestations: List[PendingAttestat
 def get_current_epoch_boundary_attestations(state: BeaconState) -> List[PendingAttestation]:
     return [
         a for a in state.current_epoch_attestations
-        if a.data.epoch_boundary_root == get_block_root(state, get_epoch_start_slot(get_current_epoch(state)))
+        if a.data.target_root == get_block_root(state, get_epoch_start_slot(get_current_epoch(state)))
     ]
 ```
 
@@ -1741,7 +1738,7 @@ def get_current_epoch_boundary_attestations(state: BeaconState) -> List[PendingA
 def get_previous_epoch_boundary_attestations(state: BeaconState) -> List[PendingAttestation]:
     return [
         a for a in state.previous_epoch_attestations
-        if a.data.epoch_boundary_root == get_block_root(state, get_epoch_start_slot(get_previous_epoch(state)))
+        if a.data.target_root == get_block_root(state, get_epoch_start_slot(get_previous_epoch(state)))
     ]
 ```
 
@@ -1759,7 +1756,7 @@ def get_previous_epoch_matching_head_attestations(state: BeaconState) -> List[Pe
 def get_winning_root_and_participants(state: BeaconState, shard: Shard) -> Tuple[Bytes32, List[ValidatorIndex]]:
     all_attestations = state.current_epoch_attestations + state.previous_epoch_attestations
     valid_attestations = [
-        a for a in all_attestations if a.data.latest_crosslink == state.latest_crosslinks[shard]
+        a for a in all_attestations if a.data.previous_crosslink == state.latest_crosslinks[shard]
     ]
     all_roots = [a.data.crosslink_data_root for a in valid_attestations]
 
@@ -1802,7 +1799,7 @@ Run the following function:
 
 ```python
 def update_justification_and_finalization(state: BeaconState) -> None:
-    new_justified_epoch = state.justified_epoch
+    new_justified_epoch = state.current_justified_epoch
     # Rotate the justification bitfield up one epoch to make room for the current epoch
     state.justification_bitfield <<= 1
     # If the previous epoch gets justified, fill the second last bit
@@ -1826,18 +1823,18 @@ def update_justification_and_finalization(state: BeaconState) -> None:
     if (bitfield >> 1) % 4 == 0b11 and state.previous_justified_epoch == current_epoch - 2:
         state.finalized_epoch = state.previous_justified_epoch
     # The 1st/2nd/3rd most recent epochs are all justified, the 1st using the 3rd as source
-    if (bitfield >> 0) % 8 == 0b111 and state.justified_epoch == current_epoch - 2:
-        state.finalized_epoch = state.justified_epoch
+    if (bitfield >> 0) % 8 == 0b111 and state.current_justified_epoch == current_epoch - 2:
+        state.finalized_epoch = state.current_justified_epoch
     # The 1st/2nd most recent epochs are both justified, the 1st using the 2nd as source
-    if (bitfield >> 0) % 4 == 0b11 and state.justified_epoch == current_epoch - 1:
-        state.finalized_epoch = state.justified_epoch
+    if (bitfield >> 0) % 4 == 0b11 and state.current_justified_epoch == current_epoch - 1:
+        state.finalized_epoch = state.current_justified_epoch
 
     # Rotate justified epochs
-    state.previous_justified_epoch = state.justified_epoch
-    state.previous_justified_root = state.justified_root
-    if new_justified_epoch != state.justified_epoch:
-        state.justified_epoch = new_justified_epoch
-        state.justified_root = get_block_root(state, get_epoch_start_slot(new_justified_epoch))
+    state.previous_justified_epoch = state.current_justified_epoch
+    state.previous_justified_root = state.current_justified_root
+    if new_justified_epoch != state.current_justified_epoch:
+        state.current_justified_epoch = new_justified_epoch
+        state.current_justified_root = get_block_root(state, get_epoch_start_slot(new_justified_epoch))
 ```
 
 #### Crosslinks
@@ -2381,19 +2378,19 @@ def process_attestation(state: BeaconState, attestation: Attestation) -> None:
     assert state.slot <= attestation.data.slot + SLOTS_PER_EPOCH
     # Can't submit attestations too quickly
     assert attestation.data.slot + MIN_ATTESTATION_INCLUSION_DELAY <= state.slot
-    # Verify that the justified epoch/root is correct
+    # Verify that the justified epoch and root is correct
     if slot_to_epoch(attestation.data.slot) >= get_current_epoch(state):
         # Case 1: current epoch attestations
-        assert attestation.data.justified_epoch == state.justified_epoch
-        assert attestation.data.justified_block_root == state.justified_root
+        assert attestation.data.source_epoch == state.current_justified_epoch
+        assert attestation.data.source_root == state.current_justified_root
     else:
         # Case 2: previous epoch attestations
-        assert attestation.data.justified_epoch == state.previous_justified_epoch
-        assert attestation.data.justified_block_root == state.previous_justified_root
+        assert attestation.data.source_epoch == state.previous_justified_epoch
+        assert attestation.data.source_root == state.previous_justified_root
     # Check that the crosslink data is valid
     acceptable_crosslink_data = {
         # Case 1: Latest crosslink matches the one in the state
-        attestation.data.latest_crosslink,
+        attestation.data.previous_crosslink,
         # Case 2: State has already been updated, state's latest crosslink matches the crosslink
         # the attestation is trying to create
         Crosslink(