diff --git a/doc/src/Developer_utils.rst b/doc/src/Developer_utils.rst
index 44210218c0..60eded42e0 100644
--- a/doc/src/Developer_utils.rst
+++ b/doc/src/Developer_utils.rst
@@ -334,10 +334,11 @@ arguments of commands in LAMMPS are parsed and to make abstractions of
 repetitive tasks.
 
 The :cpp:class:`LAMMPS_NS::ArgInfo` class provides an abstraction
-for parsing references to compute or fix styles or variables. These
-would start with a "c\_", "f\_", "v\_" followed by the ID or name of
-than instance and may be postfixed with one or two array indices
-"[<number>]" with numbers > 0.
+for parsing references to compute or fix styles, variables or custom
+integer or double properties handled by :doc:`fix property/atom <fix_property_atom>`.
+These would start with a "c\_", "f\_", "v\_", "d\_", "d2\_", "i\_", or "i2_"
+followed by the ID or name of than instance and may be postfixed with
+one or two array indices "[<number>]" with numbers > 0.
 
 A typical code segment would look like this:
 
diff --git a/src/arg_info.cpp b/src/arg_info.cpp
index a274b47b92..5063b6b471 100644
--- a/src/arg_info.cpp
+++ b/src/arg_info.cpp
@@ -30,7 +30,8 @@ using namespace LAMMPS_NS;
 
 ArgInfo::ArgInfo(const std::string &arg, int allowed) : type(NONE), dim(0), index1(-1), index2(-1)
 {
-  if ((arg.size() > 2) && (arg[1] == '_')) {
+  if (((arg.size() > 3) && (arg[1] == '2') && (arg[2] == '_'))
+      || ((arg.size() > 2) && (arg[1] == '_'))) {
     if ((arg[0] == 'c') && (allowed & COMPUTE))
       type = COMPUTE;
     else if ((arg[0] == 'f') && (allowed & FIX))
@@ -46,10 +47,11 @@ ArgInfo::ArgInfo(const std::string &arg, int allowed) : type(NONE), dim(0), inde
       name = arg;
       return;
     }
+    const int offset = (arg[1] == '_') ? 2 : 3;
 
-    std::size_t has_idx1 = arg.find('[', 2);
+    std::size_t has_idx1 = arg.find('[', offset);
     if (has_idx1 != std::string::npos) {
-      name = arg.substr(2, has_idx1 - 2);
+      name = arg.substr(offset, has_idx1 - offset);
       dim = 1;
 
       std::size_t has_idx2 = arg.find('[', has_idx1 + 1);
@@ -79,7 +81,7 @@ ArgInfo::ArgInfo(const std::string &arg, int allowed) : type(NONE), dim(0), inde
       }
     } else {
       index1 = 0;
-      name = arg.substr(2);
+      name = arg.substr(offset);
     }
   } else {
     index1 = 0;
diff --git a/unittest/utils/test_argutils.cpp b/unittest/utils/test_argutils.cpp
index a527df6fe7..c5ef19bc10 100644
--- a/unittest/utils/test_argutils.cpp
+++ b/unittest/utils/test_argutils.cpp
@@ -169,6 +169,16 @@ TEST(ArgInfo, variable2)
     ASSERT_THAT(arg.get_name(), StrEq("x"));
 }
 
+TEST(ArgInfo, variable3)
+{
+    ArgInfo arg("v_x[11][5]");
+    ASSERT_EQ(arg.get_dim(), 2);
+    ASSERT_EQ(arg.get_type(), ArgInfo::VARIABLE);
+    ASSERT_EQ(arg.get_index1(), 11);
+    ASSERT_EQ(arg.get_index2(), 5);
+    ASSERT_THAT(arg.get_name(), StrEq("x"));
+}
+
 TEST(ArgInfo, dname0)
 {
     ArgInfo arg("d_text", ArgInfo::DNAME);
@@ -179,6 +189,36 @@ TEST(ArgInfo, dname0)
     ASSERT_THAT(arg.get_name(), StrEq("text"));
 }
 
+TEST(ArgInfo, dname1)
+{
+    ArgInfo arg("d2_text", ArgInfo::DNAME | ArgInfo::INAME);
+    ASSERT_EQ(arg.get_dim(), 0);
+    ASSERT_EQ(arg.get_type(), ArgInfo::DNAME);
+    ASSERT_EQ(arg.get_index1(), 0);
+    ASSERT_EQ(arg.get_index2(), -1);
+    ASSERT_THAT(arg.get_name(), StrEq("text"));
+}
+
+TEST(ArgInfo, dname2)
+{
+    ArgInfo arg("d2_text[11]", ArgInfo::DNAME);
+    ASSERT_EQ(arg.get_dim(), 1);
+    ASSERT_EQ(arg.get_type(), ArgInfo::DNAME);
+    ASSERT_EQ(arg.get_index1(), 11);
+    ASSERT_EQ(arg.get_index2(), -1);
+    ASSERT_THAT(arg.get_name(), StrEq("text"));
+}
+
+TEST(ArgInfo, dname3)
+{
+    ArgInfo arg("d2_text[24][11]", ArgInfo::DNAME);
+    ASSERT_EQ(arg.get_dim(), 2);
+    ASSERT_EQ(arg.get_type(), ArgInfo::DNAME);
+    ASSERT_EQ(arg.get_index1(), 24);
+    ASSERT_EQ(arg.get_index2(), 11);
+    ASSERT_THAT(arg.get_name(), StrEq("text"));
+}
+
 TEST(ArgInfo, iname0)
 {
     ArgInfo arg("i_text", ArgInfo::INAME);
@@ -189,6 +229,36 @@ TEST(ArgInfo, iname0)
     ASSERT_THAT(arg.get_name(), StrEq("text"));
 }
 
+TEST(ArgInfo, iname1)
+{
+    ArgInfo arg("i2_text", ArgInfo::INAME);
+    ASSERT_EQ(arg.get_dim(), 0);
+    ASSERT_EQ(arg.get_type(), ArgInfo::INAME);
+    ASSERT_EQ(arg.get_index1(), 0);
+    ASSERT_EQ(arg.get_index2(), -1);
+    ASSERT_THAT(arg.get_name(), StrEq("text"));
+}
+
+TEST(ArgInfo, iname2)
+{
+    ArgInfo arg("i2_text[2]", ArgInfo::INAME | ArgInfo::DNAME);
+    ASSERT_EQ(arg.get_dim(), 1);
+    ASSERT_EQ(arg.get_type(), ArgInfo::INAME);
+    ASSERT_EQ(arg.get_index1(), 2);
+    ASSERT_EQ(arg.get_index2(), -1);
+    ASSERT_THAT(arg.get_name(), StrEq("text"));
+}
+
+TEST(ArgInfo, iname3)
+{
+    ArgInfo arg("i2_text[2][100]", ArgInfo::INAME | ArgInfo::DNAME);
+    ASSERT_EQ(arg.get_dim(), 2);
+    ASSERT_EQ(arg.get_type(), ArgInfo::INAME);
+    ASSERT_EQ(arg.get_index1(), 2);
+    ASSERT_EQ(arg.get_index2(), 100);
+    ASSERT_THAT(arg.get_name(), StrEq("text"));
+}
+
 TEST(ArgInfo, unsupported1)
 {
     ArgInfo arg("v_text[02][05]", ArgInfo::COMPUTE | ArgInfo::FIX);