diff --git a/apps/note/models/transactions.py b/apps/note/models/transactions.py
index 366b4527f132a5e62cd98191302625e6b4d8634d..c9c6bf699240597070db0b5f31df812eeb586bf2 100644
--- a/apps/note/models/transactions.py
+++ b/apps/note/models/transactions.py
@@ -264,6 +264,17 @@ class SpecialTransaction(Transaction):
     def type(self):
         return _('Credit') if isinstance(self.source, NoteSpecial) else _("Debit")
 
+    def is_credit(self):
+        return isinstance(self.source, NoteSpecial)
+
+    def is_debit(self):
+        return isinstance(self.destination, NoteSpecial)
+
+    def clean(self):
+        # SpecialTransaction are only possible with NoteSpecial object
+        if self.is_credit() == self.is_debit():
+            raise(ValidationError(_("A special transaction is only possible between a  Note associated to a payment method and a User or a Club")))
+
 
 class MembershipTransaction(Transaction):
     """
diff --git a/apps/scripts b/apps/scripts
index c37a6effc9217e2ffceb631f48b371f87814c1f6..ee54fca89ee247a4ba4af080dd3036d92340eade 160000
--- a/apps/scripts
+++ b/apps/scripts
@@ -1 +1 @@
-Subproject commit c37a6effc9217e2ffceb631f48b371f87814c1f6
+Subproject commit ee54fca89ee247a4ba4af080dd3036d92340eade
diff --git a/apps/treasury/models.py b/apps/treasury/models.py
index 5628504ba209058ba9bbd164d79a36c9f3cc3dcd..1e7f2a95b90de5472e24b1afdd13ff896440e5bf 100644
--- a/apps/treasury/models.py
+++ b/apps/treasury/models.py
@@ -191,7 +191,7 @@ class SpecialTransactionProxy(models.Model):
     """
     In order to keep modularity, we don't that the Note app depends on the treasury app.
     That's why we create a proxy in this app, to link special transactions and remittances.
-    If it isn't very clean, that makes what we want.
+    If it isn't very clean, it does what we want.
     """
 
     transaction = models.OneToOneField(
diff --git a/apps/treasury/signals.py b/apps/treasury/signals.py
index 188be1a7e63df48dd7fa6ea4b631133ed49693c2..b7038ab61d25d819f7c12b94a0fb98e15aeb6e0e 100644
--- a/apps/treasury/signals.py
+++ b/apps/treasury/signals.py
@@ -1,7 +1,6 @@
 # Copyright (C) 2018-2020 by BDE ENS Paris-Saclay
 # SPDX-License-Identifier: GPL-3.0-or-later
 
-from note.models import NoteSpecial
 from treasury.models import SpecialTransactionProxy, RemittanceType
 
 
@@ -9,6 +8,10 @@ def save_special_transaction(instance, created, **kwargs):
     """
     When a special transaction is created, we create its linked proxy
     """
-    if created and isinstance(instance.source, NoteSpecial) \
-            and RemittanceType.objects.filter(note=instance.source).exists():
-        SpecialTransactionProxy.objects.create(transaction=instance, remittance=None).save()
+
+    if instance.is_credit():
+        if created and RemittanceType.objects.filter(note=instance.source).exists():
+            SpecialTransactionProxy.objects.create(transaction=instance, remittance=None).save()
+    else:
+        if created and RemittanceType.objects.filter(note=instance.destination).exists():
+            SpecialTransactionProxy.objects.create(transaction=instance, remittance=None).save()
diff --git a/apps/wei/management/commands/export_wei_registrations.py b/apps/wei/management/commands/export_wei_registrations.py
new file mode 100644
index 0000000000000000000000000000000000000000..f76852c856232b7010e771161f8043733d1fdf09
--- /dev/null
+++ b/apps/wei/management/commands/export_wei_registrations.py
@@ -0,0 +1,89 @@
+# Copyright (C) 2018-2020 by BDE ENS Paris-Saclay
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from django.core.management import BaseCommand, CommandError
+from django.db.models import Q
+from django.db.models.functions import Lower
+
+from wei.models import WEIClub, Bus, BusTeam, WEIMembership
+
+
+class Command(BaseCommand):
+    help = "Export WEI registrations."
+
+    def add_arguments(self, parser):
+        parser.add_argument('--bus', '-b', choices=[bus.name for bus in Bus.objects.all()], type=str, default=None,
+                            help='Filter by bus')
+        parser.add_argument('--team', '-t', choices=[team.name for team in BusTeam.objects.all()], type=str,
+                            default=None, help='Filter by team. Type "none" if you want to select the members '
+                            + 'that are not in a team.')
+        parser.add_argument('--year', '-y', type=int, default=None,
+                            help='Select the year of the concerned WEI. Default: last year')
+        parser.add_argument('--sep', type=str, default='|',
+                            help='Select the CSV separator.')
+
+    def handle(self, *args, **options):
+        year = options["year"]
+        if year:
+            try:
+                wei = WEIClub.objects.get(year=year)
+            except WEIClub.DoesNotExist:
+                raise CommandError("The WEI of year {:d} does not exist.".format(year,))
+        else:
+            wei = WEIClub.objects.order_by('-year').first()
+
+        bus = options["bus"]
+        if bus:
+            try:
+                bus = Bus.objects.filter(wei=wei).get(name=bus)
+            except Bus.DoesNotExist:
+                raise CommandError("The bus {} does not exist or does not belong to the WEI {}.".format(bus, wei.name,))
+
+        team = options["team"]
+        if team:
+            if team.lower() == "none":
+                team = 0
+            else:
+                try:
+                    team = BusTeam.objects.filter(Q(bus=bus) | Q(wei=wei)).get(name=team)
+                    bus = team.bus
+                except BusTeam.DoesNotExist:
+                    raise CommandError("The bus {} does not exist or does not belong to the bus {} neither the wei {}."
+                                       .format(team, bus.name if bus else "<None>", wei.name,))
+
+        qs = WEIMembership.objects
+        qs = qs.filter(club=wei).order_by(
+            Lower('bus__name'),
+            Lower('team__name'),
+            'user__profile__promotion',
+            Lower('user__last_name'),
+            Lower('user__first_name'),
+        ).distinct()
+
+        if bus:
+            qs = qs.filter(bus=bus)
+
+        if team is not None:
+            qs = qs.filter(team=team if team else None)
+            
+        sep = options["sep"]
+
+        self.stdout.write("Nom|Prénom|Date de naissance|Genre|Département|Année|Section|Bus|Équipe|Rôles"
+                          .replace(sep, sep))
+
+        for membership in qs.all():
+            user = membership.user
+            registration = membership.registration
+            bus = membership.bus
+            team = membership.team
+            s = user.last_name
+            s += sep + user.first_name
+            s += sep + str(registration.birth_date)
+            s += sep + registration.get_gender_display()
+            s += sep + user.profile.get_department_display()
+            s += sep + str(user.profile.ens_year) + "A"
+            s += sep + user.profile.section_generated
+            s += sep + bus.name
+            s += sep + (team.name if team else "--")
+            s += sep + ", ".join(role.name for role in membership.roles.filter(~Q(name="Adhérent WEI")).all())
+            self.stdout.write(s)
diff --git a/apps/wei/management/commands/extract_ml_registrations.py b/apps/wei/management/commands/extract_ml_registrations.py
new file mode 100644
index 0000000000000000000000000000000000000000..b67bf10b2f723624db36afee3cfbea5dede32b4e
--- /dev/null
+++ b/apps/wei/management/commands/extract_ml_registrations.py
@@ -0,0 +1,52 @@
+# Copyright (C) 2018-2020 by BDE ENS Paris-Saclay
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from datetime import date
+
+from django.core.management import BaseCommand
+from django.db.models import Q
+from member.models import Membership, Club
+from wei.models import WEIClub
+
+
+class Command(BaseCommand):
+    help = "Get mailing list registrations from the last wei. " \
+           "Usage: manage.py extract_ml_registrations -t {events,art,sport}. " \
+           "You can write this into a file with a pipe, then paste the document into your mail manager."
+
+    def add_arguments(self, parser):
+        parser.add_argument('--type', '-t', choices=["members", "clubs", "events", "art", "sport"], default="members",
+                            help='Select the type of the mailing list (default members)')
+        parser.add_argument('--year', '-y', type=int, default=None,
+                            help='Select the year of the concerned WEI. Default: last year')
+
+    def handle(self, *args, **options):
+        if options["type"] == "members":
+            for membership in Membership.objects.filter(
+                club__name="BDE",
+                date_start__lte=date.today(),
+                date_end__gte=date.today(),
+            ).all():
+                self.stdout.write(membership.user.email)
+            return
+
+        if options["type"] == "clubs":
+            for club in Club.objects.all():
+                self.stdout.write(club.email)
+            return
+
+        if options["year"] is None:
+            wei = WEIClub.objects.order_by('-year').first()
+        else:
+            wei = WEIClub.objects.filter(year=options["year"])
+            if wei.exists():
+                wei = wei.get()
+            else:
+                wei = WEIClub.objects.order_by('-year').first()
+                self.stderr.write(self.style.WARNING("Warning: there was no WEI in year " + str(options["year"]) + ". "
+                                                     + "Assuming the last WEI (year " + str(wei.year) + ")"))
+        q = Q(ml_events_registration=True) if options["type"] == "events" else Q(ml_art_registration=True)\
+            if options["type"] == "art" else Q(ml_sport_registration=True)
+        registrations = wei.users.filter(q)
+        for registration in registrations.all():
+            self.stdout.write(registration.user.email)
diff --git a/apps/wei/management/commands/wei_algorithm.py b/apps/wei/management/commands/wei_algorithm.py
new file mode 100644
index 0000000000000000000000000000000000000000..01640720fcc1e31a0c801c2ed779d0dedd036f86
--- /dev/null
+++ b/apps/wei/management/commands/wei_algorithm.py
@@ -0,0 +1,15 @@
+# Copyright (C) 2018-2020 by BDE ENS Paris-Saclay
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from django.core.management import BaseCommand
+from wei.forms import CurrentSurvey
+
+
+class Command(BaseCommand):
+    help = "Attribute to each first year member a bus for the WEI"
+
+    def handle(self, *args, **options):
+        """
+        Run the WEI algorithm to attribute a bus to each first year member.
+        """
+        CurrentSurvey.get_algorithm_class()().run_algorithm()
diff --git a/requirements/base.txt b/requirements/base.txt
index 9c978ed03288cd7c53da8a9be59c82bb3e548bbb..7da788e35c9c6b20964ce0e4a779e3934bbd0444 100644
--- a/requirements/base.txt
+++ b/requirements/base.txt
@@ -11,7 +11,7 @@ django-tables2==2.1.0
 docutils==0.14
 idna==2.8
 oauthlib==3.1.0
-Pillow==6.1.0
+Pillow==7.1.2
 python3-openid==3.1.0
 pytz==2019.1
 requests==2.22.0