runtime(sdc): Add underscore to sdc flags in syntax file (#6201)
diff --git a/runtime/syntax/sdc.vim b/runtime/syntax/sdc.vim
index 0ca9bec..dbfa35e 100644
--- a/runtime/syntax/sdc.vim
+++ b/runtime/syntax/sdc.vim
@@ -25,7 +25,7 @@
syn keyword sdcCreateOperations create_clock create_timing_netlist update_timing_netlist
" command flags highlighting
-syn match sdcFlags "[[:space:]]-[[:alpha:]]*\>"
+syn match sdcFlags "[[:space:]]-[[:alpha:]_]*\>"
" Define the default highlighting.
hi def link sdcCollections Repeat