diff --git a/tools/aconfig/src/commands.rs b/tools/aconfig/src/commands.rs
index 50049d5..7ae1219 100644
--- a/tools/aconfig/src/commands.rs
+++ b/tools/aconfig/src/commands.rs
@@ -23,12 +23,12 @@
 use crate::codegen::cpp::generate_cpp_code;
 use crate::codegen::java::generate_java_code;
 use crate::codegen::rust::generate_rust_code;
-use crate::storage::generate_storage_files;
-
+use crate::dump::DumpFormat;
 use crate::protos::{
     ParsedFlagExt, ProtoFlagMetadata, ProtoFlagPermission, ProtoFlagState, ProtoParsedFlag,
     ProtoParsedFlags, ProtoTracepoint,
 };
+use crate::storage::generate_storage_files;
 
 pub struct Input {
     pub source: String,
@@ -279,15 +279,6 @@
     Ok(output)
 }
 
-#[derive(Copy, Clone, Debug, PartialEq, Eq, ValueEnum)]
-pub enum DumpFormat {
-    Text,
-    Verbose,
-    Protobuf,
-    Textproto,
-    Bool,
-}
-
 pub fn dump_parsed_flags(
     mut input: Vec<Input>,
     format: DumpFormat,
@@ -297,55 +288,7 @@
         input.iter_mut().map(|i| i.try_parse_flags()).collect();
     let parsed_flags: ProtoParsedFlags =
         crate::protos::parsed_flags::merge(individually_parsed_flags?, dedup)?;
-
-    let mut output = Vec::new();
-    match format {
-        DumpFormat::Text => {
-            for parsed_flag in parsed_flags.parsed_flag.into_iter() {
-                let line = format!(
-                    "{} [{}]: {:?} + {:?}\n",
-                    parsed_flag.fully_qualified_name(),
-                    parsed_flag.container(),
-                    parsed_flag.permission(),
-                    parsed_flag.state()
-                );
-                output.extend_from_slice(line.as_bytes());
-            }
-        }
-        DumpFormat::Verbose => {
-            for parsed_flag in parsed_flags.parsed_flag.into_iter() {
-                let sources: Vec<_> =
-                    parsed_flag.trace.iter().map(|tracepoint| tracepoint.source()).collect();
-                let line = format!(
-                    "{} [{}]: {:?} + {:?} ({})\n",
-                    parsed_flag.fully_qualified_name(),
-                    parsed_flag.container(),
-                    parsed_flag.permission(),
-                    parsed_flag.state(),
-                    sources.join(", ")
-                );
-                output.extend_from_slice(line.as_bytes());
-            }
-        }
-        DumpFormat::Protobuf => {
-            parsed_flags.write_to_vec(&mut output)?;
-        }
-        DumpFormat::Textproto => {
-            let s = protobuf::text_format::print_to_string_pretty(&parsed_flags);
-            output.extend_from_slice(s.as_bytes());
-        }
-        DumpFormat::Bool => {
-            for parsed_flag in parsed_flags.parsed_flag.into_iter() {
-                let line = format!(
-                    "{}={:?}\n",
-                    parsed_flag.fully_qualified_name(),
-                    parsed_flag.state() == ProtoFlagState::ENABLED
-                );
-                output.extend_from_slice(line.as_bytes());
-            }
-        }
-    }
-    Ok(output)
+    crate::dump::dump_parsed_flags(parsed_flags.parsed_flag.into_iter(), format)
 }
 
 fn find_unique_package(parsed_flags: &[ProtoParsedFlag]) -> Option<&str> {
@@ -622,36 +565,16 @@
     }
 
     #[test]
-    fn test_dump_text_format() {
+    fn test_dump() {
         let input = parse_test_flags_as_input();
-        let bytes = dump_parsed_flags(vec![input], DumpFormat::Text, false).unwrap();
-        let text = std::str::from_utf8(&bytes).unwrap();
-        assert!(
-            text.contains("com.android.aconfig.test.disabled_ro [system]: READ_ONLY + DISABLED")
-        );
-    }
-
-    #[test]
-    fn test_dump_protobuf_format() {
-        let expected = protobuf::text_format::parse_from_str::<ProtoParsedFlags>(
-            crate::test::TEST_FLAGS_TEXTPROTO,
+        let bytes = dump_parsed_flags(
+            vec![input],
+            DumpFormat::Custom("{fully_qualified_name}".to_string()),
+            false,
         )
-        .unwrap()
-        .write_to_bytes()
         .unwrap();
-
-        let input = parse_test_flags_as_input();
-        let actual = dump_parsed_flags(vec![input], DumpFormat::Protobuf, false).unwrap();
-
-        assert_eq!(expected, actual);
-    }
-
-    #[test]
-    fn test_dump_textproto_format() {
-        let input = parse_test_flags_as_input();
-        let bytes = dump_parsed_flags(vec![input], DumpFormat::Textproto, false).unwrap();
         let text = std::str::from_utf8(&bytes).unwrap();
-        assert_eq!(crate::test::TEST_FLAGS_TEXTPROTO.trim(), text.trim());
+        assert!(text.contains("com.android.aconfig.test.disabled_ro"));
     }
 
     #[test]
diff --git a/tools/aconfig/src/dump.rs b/tools/aconfig/src/dump.rs
new file mode 100644
index 0000000..410c392
--- /dev/null
+++ b/tools/aconfig/src/dump.rs
@@ -0,0 +1,240 @@
+/*
+ * Copyright (C) 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+use crate::protos::{ParsedFlagExt, ProtoFlagMetadata, ProtoFlagState, ProtoTracepoint};
+use crate::protos::{ProtoParsedFlag, ProtoParsedFlags};
+use anyhow::Result;
+use protobuf::Message;
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub enum DumpFormat {
+    Protobuf,
+    Textproto,
+    Custom(String),
+}
+
+impl TryFrom<&str> for DumpFormat {
+    type Error = anyhow::Error;
+
+    fn try_from(value: &str) -> std::result::Result<Self, Self::Error> {
+        match value {
+            // protobuf formats
+            "protobuf" => Ok(Self::Protobuf),
+            "textproto" => Ok(Self::Textproto),
+
+            // old formats now implemented as aliases to custom format
+            "text" => Ok(Self::Custom(
+                "{fully_qualified_name} [{container}]: {permission} + {state}".to_owned(),
+            )),
+            "verbose" => Ok(Self::Custom(
+                "{fully_qualified_name} [{container}]: {permission} + {state} ({trace:paths})"
+                    .to_owned(),
+            )),
+            "bool" => Ok(Self::Custom("{fully_qualified_name}={state:bool}".to_owned())),
+
+            // custom format
+            _ => Ok(Self::Custom(value.to_owned())),
+        }
+    }
+}
+
+pub fn dump_parsed_flags<I>(parsed_flags_iter: I, format: DumpFormat) -> Result<Vec<u8>>
+where
+    I: Iterator<Item = ProtoParsedFlag>,
+{
+    let mut output = Vec::new();
+    match format {
+        DumpFormat::Protobuf => {
+            let parsed_flags =
+                ProtoParsedFlags { parsed_flag: parsed_flags_iter.collect(), ..Default::default() };
+            parsed_flags.write_to_vec(&mut output)?;
+        }
+        DumpFormat::Textproto => {
+            let parsed_flags =
+                ProtoParsedFlags { parsed_flag: parsed_flags_iter.collect(), ..Default::default() };
+            let s = protobuf::text_format::print_to_string_pretty(&parsed_flags);
+            output.extend_from_slice(s.as_bytes());
+        }
+        DumpFormat::Custom(format) => {
+            for flag in parsed_flags_iter {
+                dump_custom_format(&flag, &format, &mut output);
+            }
+        }
+    }
+    Ok(output)
+}
+
+fn dump_custom_format(flag: &ProtoParsedFlag, format: &str, output: &mut Vec<u8>) {
+    fn format_trace(trace: &[ProtoTracepoint]) -> String {
+        trace
+            .iter()
+            .map(|tracepoint| {
+                format!(
+                    "{}: {:?} + {:?}",
+                    tracepoint.source(),
+                    tracepoint.permission(),
+                    tracepoint.state()
+                )
+            })
+            .collect::<Vec<_>>()
+            .join(", ")
+    }
+
+    fn format_trace_paths(trace: &[ProtoTracepoint]) -> String {
+        trace.iter().map(|tracepoint| tracepoint.source()).collect::<Vec<_>>().join(", ")
+    }
+
+    fn format_metadata(metadata: &ProtoFlagMetadata) -> String {
+        format!("{:?}", metadata.purpose())
+    }
+
+    let mut str = format
+        // ProtoParsedFlag fields
+        .replace("{package}", flag.package())
+        .replace("{name}", flag.name())
+        .replace("{namespace}", flag.namespace())
+        .replace("{description}", flag.description())
+        .replace("{bug}", &flag.bug.join(", "))
+        .replace("{state}", &format!("{:?}", flag.state()))
+        .replace("{state:bool}", &format!("{}", flag.state() == ProtoFlagState::ENABLED))
+        .replace("{permission}", &format!("{:?}", flag.permission()))
+        .replace("{trace}", &format_trace(&flag.trace))
+        .replace("{trace:paths}", &format_trace_paths(&flag.trace))
+        .replace("{is_fixed_read_only}", &format!("{}", flag.is_fixed_read_only()))
+        .replace("{is_exported}", &format!("{}", flag.is_exported()))
+        .replace("{container}", flag.container())
+        .replace("{metadata}", &format_metadata(&flag.metadata))
+        // ParsedFlagExt functions
+        .replace("{fully_qualified_name}", &flag.fully_qualified_name());
+    str.push('\n');
+    output.extend_from_slice(str.as_bytes());
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::protos::ProtoParsedFlags;
+    use crate::test::parse_test_flags;
+    use protobuf::Message;
+
+    fn parse_enabled_ro_flag() -> ProtoParsedFlag {
+        parse_test_flags().parsed_flag.into_iter().find(|pf| pf.name() == "enabled_ro").unwrap()
+    }
+
+    #[test]
+    fn test_dumpformat_from_str() {
+        // supported format types
+        assert_eq!(DumpFormat::try_from("protobuf").unwrap(), DumpFormat::Protobuf);
+        assert_eq!(DumpFormat::try_from("textproto").unwrap(), DumpFormat::Textproto);
+        assert_eq!(
+            DumpFormat::try_from("foobar").unwrap(),
+            DumpFormat::Custom("foobar".to_owned())
+        );
+    }
+
+    #[test]
+    fn test_dump_parsed_flags_protobuf_format() {
+        let expected = protobuf::text_format::parse_from_str::<ProtoParsedFlags>(
+            crate::test::TEST_FLAGS_TEXTPROTO,
+        )
+        .unwrap()
+        .write_to_bytes()
+        .unwrap();
+        let parsed_flags = parse_test_flags();
+        let actual =
+            dump_parsed_flags(parsed_flags.parsed_flag.into_iter(), DumpFormat::Protobuf).unwrap();
+        assert_eq!(expected, actual);
+    }
+
+    #[test]
+    fn test_dump_parsed_flags_textproto_format() {
+        let parsed_flags = parse_test_flags();
+        let bytes =
+            dump_parsed_flags(parsed_flags.parsed_flag.into_iter(), DumpFormat::Textproto).unwrap();
+        let text = std::str::from_utf8(&bytes).unwrap();
+        assert_eq!(crate::test::TEST_FLAGS_TEXTPROTO.trim(), text.trim());
+    }
+
+    #[test]
+    fn test_dump_parsed_flags_custom_format() {
+        macro_rules! assert_dump_parsed_flags_custom_format_contains {
+            ($format:expr, $expected:expr) => {
+                let parsed_flags = parse_test_flags();
+                let bytes = dump_parsed_flags(
+                    parsed_flags.parsed_flag.into_iter(),
+                    $format.try_into().unwrap(),
+                )
+                .unwrap();
+                let text = std::str::from_utf8(&bytes).unwrap();
+                assert!(text.contains($expected));
+            };
+        }
+
+        // custom format
+        assert_dump_parsed_flags_custom_format_contains!(
+            "{fully_qualified_name}={permission} + {state}",
+            "com.android.aconfig.test.enabled_ro=READ_ONLY + ENABLED"
+        );
+
+        // aliases
+        assert_dump_parsed_flags_custom_format_contains!(
+            "text",
+            "com.android.aconfig.test.enabled_ro [system]: READ_ONLY + ENABLED"
+        );
+        assert_dump_parsed_flags_custom_format_contains!(
+            "verbose",
+            "com.android.aconfig.test.enabled_ro [system]: READ_ONLY + ENABLED (tests/test.aconfig, tests/first.values, tests/second.values)"
+        );
+        assert_dump_parsed_flags_custom_format_contains!(
+            "bool",
+            "com.android.aconfig.test.enabled_ro=true"
+        );
+    }
+
+    #[test]
+    fn test_dump_custom_format() {
+        macro_rules! assert_custom_format {
+            ($format:expr, $expected:expr) => {
+                let flag = parse_enabled_ro_flag();
+                let mut bytes = vec![];
+                dump_custom_format(&flag, $format, &mut bytes);
+                let text = std::str::from_utf8(&bytes).unwrap();
+                assert_eq!(text, $expected);
+            };
+        }
+
+        assert_custom_format!("{package}", "com.android.aconfig.test\n");
+        assert_custom_format!("{name}", "enabled_ro\n");
+        assert_custom_format!("{namespace}", "aconfig_test\n");
+        assert_custom_format!("{description}", "This flag is ENABLED + READ_ONLY\n");
+        assert_custom_format!("{bug}", "abc\n");
+        assert_custom_format!("{state}", "ENABLED\n");
+        assert_custom_format!("{state:bool}", "true\n");
+        assert_custom_format!("{permission}", "READ_ONLY\n");
+        assert_custom_format!("{trace}", "tests/test.aconfig: READ_WRITE + DISABLED, tests/first.values: READ_WRITE + DISABLED, tests/second.values: READ_ONLY + ENABLED\n");
+        assert_custom_format!(
+            "{trace:paths}",
+            "tests/test.aconfig, tests/first.values, tests/second.values\n"
+        );
+        assert_custom_format!("{is_fixed_read_only}", "false\n");
+        assert_custom_format!("{is_exported}", "false\n");
+        assert_custom_format!("{container}", "system\n");
+        assert_custom_format!("{metadata}", "PURPOSE_BUGFIX\n");
+
+        assert_custom_format!("name={name}|state={state}", "name=enabled_ro|state=ENABLED\n");
+        assert_custom_format!("{state}{state}{state}", "ENABLEDENABLEDENABLED\n");
+    }
+}
diff --git a/tools/aconfig/src/main.rs b/tools/aconfig/src/main.rs
index 63a50c8..08e8b97 100644
--- a/tools/aconfig/src/main.rs
+++ b/tools/aconfig/src/main.rs
@@ -26,13 +26,16 @@
 
 mod codegen;
 mod commands;
+mod dump;
 mod protos;
 mod storage;
 
+use dump::DumpFormat;
+
 #[cfg(test)]
 mod test;
 
-use commands::{CodegenMode, DumpFormat, Input, OutputFile};
+use commands::{CodegenMode, Input, OutputFile};
 
 fn cli() -> Command {
     Command::new("aconfig")
@@ -103,7 +106,7 @@
                 .arg(
                     Arg::new("format")
                         .long("format")
-                        .value_parser(EnumValueParser::<commands::DumpFormat>::new())
+                        .value_parser(|s: &str| DumpFormat::try_from(s))
                         .default_value("text"),
                 )
                 .arg(Arg::new("dedup").long("dedup").num_args(0).action(ArgAction::SetTrue))
@@ -250,7 +253,7 @@
             let format = get_required_arg::<DumpFormat>(sub_matches, "format")
                 .context("failed to dump previously parsed flags")?;
             let dedup = get_required_arg::<bool>(sub_matches, "dedup")?;
-            let output = commands::dump_parsed_flags(input, *format, *dedup)?;
+            let output = commands::dump_parsed_flags(input, format.clone(), *dedup)?;
             let path = get_required_arg::<String>(sub_matches, "out")?;
             write_output_to_file_or_stdout(path, &output)?;
         }