diff --git a/code/heuristic-q01.py b/code/heuristic-q01.py
index 47b27fb..8bf4359 100644
--- a/code/heuristic-q01.py
+++ b/code/heuristic-q01.py
@@ -5,7 +5,7 @@ from heudiconv.utils import SeqInfo
 
 # https://heudiconv.readthedocs.io/en/latest/heuristics.html#populate-intended-for-opts
 POPULATE_INTENDED_FOR_OPTS = {
-    "matching_parameters": ["ImagingVolume", "Shims"],
+    "matching_parameters": ["CustomAcquisitionLabel", "ImagingVolume", "Shims"],
     "criterion": "Closest",
 }
 
@@ -45,19 +45,18 @@ def infotodict(
     rest = create_key("{bids_subject_session_dir}/func/{bids_subject_session_prefix}_task-rest_bold")
     restvida = create_key("{bids_subject_session_dir}/func/{bids_subject_session_prefix}_task-restvida_bold")
     restvidn = create_key("{bids_subject_session_dir}/func/{bids_subject_session_prefix}_task-restvidn_bold")
-    fmap_ap = create_key("{bids_subject_session_dir}/fmap/{bids_subject_session_prefix}_dir-ap_run-{item}_epi")
-    fmap_pa = create_key("{bids_subject_session_dir}/fmap/{bids_subject_session_prefix}_dir-pa_run-{item}_epi")
-    dwi_b1200 = create_key("{bids_subject_session_dir}/dwi/{bids_subject_session_prefix}_acq-b1200_dwi")
-    ref_b1200 = create_key("{bids_subject_session_dir}/dwi/{bids_subject_session_prefix}_acq-b1200_sbref")
-    dwi_mshell = create_key("{bids_subject_session_dir}/dwi/{bids_subject_session_prefix}_acq-mshell_dwi")
-    ref_mshell = create_key("{bids_subject_session_dir}/dwi/{bids_subject_session_prefix}_acq-mshell_sbref")
+    dwi_b1200 = create_key("{bids_subject_session_dir}/dwi/{bids_subject_session_prefix}_acq-b1200_dir-PA_dwi")
+    ref_b1200 = create_key("{bids_subject_session_dir}/fmap/{bids_subject_session_prefix}_acq-b1200_dir-AP_epi")
+    dwi_mshell = create_key("{bids_subject_session_dir}/dwi/{bids_subject_session_prefix}_acq-mshell_dir-PA_dwi")
+    ref_mshell = create_key("{bids_subject_session_dir}/fmap/{bids_subject_session_prefix}_acq-mshell_dir-AP_epi")
 
-    # generate fieldmap keys with fixed run labels for explicitly declared runs
+    # generate fieldmap keys with fixed acq labels for explicitly declared runs
+    run_to_task = {"1": "rest", "2": "restvidn", "3": "restvida"}  # that was the intention
     fmap_explicit_keys = {
-        (dirlabel, runlabel): create_key(
-            f"{{bids_subject_session_dir}}/fmap/{{bids_subject_session_prefix}}_dir-{dirlabel}_run-{runlabel}_epi"
+        (dirlabel, tasklabel): create_key(
+            f"{{bids_subject_session_dir}}/fmap/{{bids_subject_session_prefix}}_acq-{tasklabel}_dir-{dirlabel}_epi"
         )
-        for dirlabel, runlabel in product(("ap", "pa"), ("1", "2", "3"))
+        for dirlabel, tasklabel in product(("ap", "pa"), ("rest", "restvidn", "restvida"))
     }
 
     info: dict[tuple[str, tuple[str, ...], None], list[str]] = {
@@ -66,8 +65,6 @@ def infotodict(
         rest: [],
         restvida: [],
         restvidn: [],
-        fmap_ap: [],
-        fmap_pa: [],
         dwi_b1200: [],
         ref_b1200: [],
         dwi_mshell: [],
@@ -77,6 +74,9 @@ def infotodict(
     # also include the generated keys
     info.update({k: [] for k in fmap_explicit_keys.values()})
 
+    # keep track of last task (potentially for field maps)
+    last_task = None
+
     for s in seqinfo:
         """
         The namedtuple `s` contains the following fields:
@@ -116,6 +116,7 @@ def infotodict(
                 info[restvida].append(s.series_id)
             if m.group("task") == "restvidn":
                 info[restvidn].append(s.series_id)
+            last_task = m.group("task")
 
         elif (m := dwi_regex.search(s.protocol_name)) is not None:
             if "b1200" in m.group("label") and not s.is_derived:
@@ -131,25 +132,20 @@ def infotodict(
 
         elif (m := fmap_regex.search(s.protocol_name)) is not None:
             if m.group("run") is None:
-                # implicit run numbering
-                if m.group("dir") == "ap":
-                    info[fmap_ap].append(s.series_id)
-                elif m.group("dir") == "pa":
-                    info[fmap_pa].append(s.series_id)
+                # no explicit run numbering
+                target_task = last_task if last_task is not None else "unknown"
             else:
                 # explicit run numbering
-                key = fmap_explicit_keys.get((m.group("dir"), m.group("run")))
-                if key is None:
-                    # unexpected label combination, ignore
-                    continue
-                info[key].append(s.series_id)
+                target_task = run_to_task.get(m.group("run"), "unknown")
+            key = fmap_explicit_keys.get((m.group("dir"), target_task))
+            if key is None:
+                # unexpected label combination, ignore
+                continue
+            info[key].append(s.series_id)
 
     # deduplicate
     removed = []
     for key, sid_list in info.items():
-        if key not in {fmap_ap, fmap_pa}:
-            # we allow (expect) run identifiers in field maps
-            continue
         if len(sid_list) > 1:
             # all other should be unique, keep last in case of repetitions
             removed.extend(sid_list[:-1])