diff --git a/doc-values/value-mask-mode.go b/doc-values/value-mask-mode.go
new file mode 100644
index 0000000..945ffc8
--- /dev/null
+++ b/doc-values/value-mask-mode.go
@@ -0,0 +1,123 @@
+package docvalues
+
+import (
+	protocol "github.com/tliron/glsp/protocol_3_16"
+	"regexp"
+)
+
+type MaskModeInvalidError struct{}
+
+func (e MaskModeInvalidError) Error() string {
+	return "This mask is not valid. It must be a 4-digit octal number."
+}
+
+type MaskModeValue struct{}
+
+func (v MaskModeValue) GetTypeDescription() []string {
+	return []string{
+		"File mode mask",
+		"4-digit octal number",
+		"Example: 0000",
+		"1st digit: setuid, setgid, sticky",
+		"2nd digit: user permissions",
+		"3rd digit: group permissions",
+		"4th digit: other permissions",
+	}
+}
+
+var maskModePattern = regexp.MustCompile("^[0-7]{4}$")
+
+func (v MaskModeValue) CheckIsValid(value string) []*InvalidValue {
+	if !maskModePattern.MatchString(value) {
+		return []*InvalidValue{{
+			Err:   MaskModeInvalidError{},
+			Start: 0,
+			End:   uint32(len(value)),
+		}}
+	}
+
+	return []*InvalidValue{}
+}
+
+func (v MaskModeValue) FetchCompletions(line string, cursor uint32) []protocol.CompletionItem {
+	kind := protocol.CompletionItemKindValue
+
+	perm0644 := "0644"
+	perm0755 := "0755"
+	perm0777 := "0777"
+	perm0400 := "0400"
+	perm0600 := "0600"
+	perm0666 := "0666"
+	perm0700 := "0700"
+	perm0444 := "0444"
+	perm0111 := "0111"
+	perm0555 := "0555"
+
+	return []protocol.CompletionItem{
+		{
+			Label:         "0000",
+			Documentation: "No permissions",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0644 (-rw-r--r--)",
+			InsertText:    &perm0644,
+			Documentation: "Read/write for owner, read for others",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0755 (-rwxr-xr-x)",
+			InsertText:    &perm0755,
+			Documentation: "Read/write/execute for owner, read/execute for others",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0777 (-rwxrwxrwx)",
+			InsertText:    &perm0777,
+			Documentation: "Read/write/execute for all",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0400 (-r--------)",
+			InsertText:    &perm0400,
+			Documentation: "Read for owner",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0600 (-rw-------)",
+			InsertText:    &perm0600,
+			Documentation: "Read/write for owner",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0666 (-rw-rw-rw-)",
+			InsertText:    &perm0666,
+			Documentation: "Read/write for all",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0700 (-rwx------)",
+			InsertText:    &perm0700,
+			Documentation: "Read/write/execute for owner",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0444 (-r--r--r--)",
+			InsertText:    &perm0444,
+			Documentation: "Read for all",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0111 (-x--x--x)",
+			InsertText:    &perm0111,
+			Documentation: "Execute for all",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0555 (-r-xr-xr-x)",
+			InsertText:    &perm0555,
+			Documentation: "Read/execute for all",
+			Kind:          &kind,
+		},
+	}
+}
diff --git a/doc-values/value-umask.go b/doc-values/value-umask.go
new file mode 100644
index 0000000..ed4b54a
--- /dev/null
+++ b/doc-values/value-umask.go
@@ -0,0 +1,112 @@
+package docvalues
+
+import (
+	"regexp"
+
+	protocol "github.com/tliron/glsp/protocol_3_16"
+)
+
+type UmaskInvalidError struct{}
+
+func (e UmaskInvalidError) Error() string {
+	return "This mask is not valid. It must be a 4-digit octal number."
+}
+
+type UmaskValue struct{}
+
+func (v UmaskValue) GetTypeDescription() []string {
+	return []string{
+		"File mode mask",
+		"4-digit octal number",
+		"Example: 0000",
+		"1st digit: setuid, setgid, sticky",
+		"2nd digit: user permissions",
+		"3rd digit: group permissions",
+		"4th digit: other permissions",
+	}
+}
+
+var umaskPattern = regexp.MustCompile("^[0-7]{4}$")
+
+func (v UmaskValue) CheckIsValid(value string) []*InvalidValue {
+	if !umaskPattern.MatchString(value) {
+		return []*InvalidValue{{
+			Err:   UmaskInvalidError{},
+			Start: 0,
+			End:   uint32(len(value)),
+		}}
+	}
+
+	return []*InvalidValue{}
+}
+
+func (v UmaskValue) FetchCompletions(line string, cursor uint32) []protocol.CompletionItem {
+	kind := protocol.CompletionItemKindValue
+
+	return []protocol.CompletionItem{
+		{
+			Label:         "0000",
+			Documentation: "Files: rwxrwxrwx Directories: rwxrwxrwx",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0022",
+			Documentation: "Files: rwxr-xr-x Directories: rwxr-xr-x",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0077",
+			Documentation: "Files: rwx------ Directories: rwx------",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0177",
+			Documentation: "Files: rw------- Directories: rw-------",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0277",
+			Documentation: "Files: r-x------ Directories: r-x------",
+		},
+		{
+			Label:         "0027",
+			Documentation: "Files: rwxr-x--- Directories: rwxr-x---",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0070",
+			Documentation: "Files: rwx---rwx Directories: rwx---rwx",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0222",
+			Documentation: "Files: r--r--r-- Directories: r--r--r--",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0333",
+			Documentation: "Files: r--r--r-- Directories: r--r--r--",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0444",
+			Documentation: "Files: r--r--r-- Directories: r--r--r--",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0555",
+			Documentation: "Files: r-xr-xr-x Directories: r-xr-xr-x",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0666",
+			Documentation: "Files: rw-rw-rw- Directories: rw-rw-rw-",
+			Kind:          &kind,
+		},
+		{
+			Label:         "0777",
+			Documentation: "Files: rwxrwxrwx Directories: rwxrwxrwx",
+			Kind:          &kind,
+		},
+	}
+}