diff --git a/src/python/jw/pkg/cmds/projects/BaseCmdPkgRelations.py b/src/python/jw/pkg/cmds/projects/BaseCmdPkgRelations.py
index 433f76d1..42dc977e 100644
--- a/src/python/jw/pkg/cmds/projects/BaseCmdPkgRelations.py
+++ b/src/python/jw/pkg/cmds/projects/BaseCmdPkgRelations.py
@@ -1,5 +1,7 @@
 from __future__ import annotations
 
+import re
+
 from typing import TYPE_CHECKING
 
 from .Cmd import Cmd, Parent
@@ -11,23 +13,27 @@ if TYPE_CHECKING:
 
 class BaseCmdPkgRelations(Cmd):
 
+    arg_sep = r'[,\s|]'
+
     def pkg_relations(self, rel_type: str, args: Namespace) -> str:
 
         return args.delimiter.join(
             pkg_relations_list(
                 self.app,
                 rel_type = rel_type,
-                flavours = args.flavours.split(','),
+                flavours = re.split(self.arg_sep, args.flavours),
                 seed_pkgs = args.modules,
-                subsections = None
-                if args.subsections is None else args.subsections.split(','),
+                subsections = (
+                    None if args.subsections is None else
+                    re.split(self.arg_sep, args.subsections)
+                ),
                 no_subpackages = args.no_subpackages,
                 dont_strip_revision = args.dont_strip_revision,
                 expand_semver_revision_range = args.expand_semver_revision_range,
                 syntax = VersionSyntax[args.syntax.replace('-', '_')],
                 recursive = args.recursive,
                 dont_expand_version_macros = args.dont_expand_version_macros,
-                ignore = set(args.ignore.split(',')),
+                ignore = set(re.split(self.arg_sep, args.ignore)),
                 quote = args.quote,
                 skip_excluded = args.skip_excluded,
                 hide_self = args.hide_self,
@@ -49,7 +55,7 @@ class BaseCmdPkgRelations(Cmd):
             '--subsections',
             nargs = '?',
             default = None,
-            help = 'Subsections to consider, comma-separated',
+            help = 'Subsections to consider, separated by comma or whitespace',
         )
         parser.add_argument(
             '-d',
@@ -59,7 +65,9 @@ class BaseCmdPkgRelations(Cmd):
             help = 'Output words delimiter'
         )
         parser.add_argument(
-            'flavours', help = 'Dependency flavours (run, build, devel, release)'
+            'flavours',
+            help = 'Dependency flavours (run, build, devel, release), '
+            'separated by comma or whitespace'
         )
         parser.add_argument('modules', nargs = '*', help = 'Modules')
         parser.add_argument(