diff --git a/models/workflow/plantuml.go b/models/workflow/plantuml.go
index 2903313..533f9c0 100644
--- a/models/workflow/plantuml.go
+++ b/models/workflow/plantuml.go
@@ -15,31 +15,32 @@ import (
 // PlantUML export
 // ---------------------------------------------------------------------------
 
-// plantUMLProcedures defines the !procedure blocks for each resource type.
-// These make the output valid, renderable PlantUML while remaining parseable
-// by ExtractFromPlantUML (which already skips lines containing "!procedure").
+// plantUMLProcedures defines !procedure blocks for each resource type.
+// Parameters use the $var/$name convention of PlantUML preprocessor v2.
+// Calls are written WITHOUT inline comments (comment on the following line)
+// to avoid the "assumed sequence diagram" syntax error.
 const plantUMLProcedures = `!procedure Processing($var, $name)
-  component "$name" as $var <<Processing>>
+component "$name" as $var <<Processing>>
 !endprocedure
 
 !procedure Data($var, $name)
-  file "$name" as $var <<Data>>
+file "$name" as $var <<Data>>
 !endprocedure
 
 !procedure Storage($var, $name)
-  database "$name" as $var <<Storage>>
+database "$name" as $var <<Storage>>
 !endprocedure
 
 !procedure ComputeUnit($var, $name)
-  node "$name" as $var <<ComputeUnit>>
+node "$name" as $var <<ComputeUnit>>
 !endprocedure
 
 !procedure WorkflowEvent($var, $name)
-  usecase "$name" as $var <<WorkflowEvent>>
+usecase "$name" as $var <<WorkflowEvent>>
 !endprocedure
 
 !procedure Workflow($var, $name)
-  frame "$name" as $var <<Workflow>>
+frame "$name" as $var <<Workflow>>
 !endprocedure
 `
 
@@ -72,11 +73,10 @@ func (w *Workflow) ToPlantUML() string {
 		if src == "" || dst == "" {
 			continue
 		}
-		line := fmt.Sprintf("%s --> %s", src, dst)
+		sb.WriteString(fmt.Sprintf("%s --> %s\n", src, dst))
 		if comment := plantUMLLinkComment(link); comment != "" {
-			line += " ' " + comment
+			sb.WriteString("' " + comment + "\n")
 		}
-		sb.WriteString(line + "\n")
 	}
 
 	sb.WriteString("\n@enduml\n")
@@ -146,11 +146,13 @@ func plantUMLItemLine(varName string, item graph.GraphItem) string {
 }
 
 func plantUMLResourceLine(macro, varName string, res resources.ResourceInterface) string {
-	line := fmt.Sprintf("%s(%s, \"%s\")", macro, varName, res.GetName())
+	decl := fmt.Sprintf("%s(%s, \"%s\")", macro, varName, res.GetName())
 	if comment := plantUMLResourceComment(res); comment != "" {
-		line += " ' " + comment
+		// Comment on the line AFTER the declaration. ExtractFromPlantUML uses
+		// look-ahead to merge it back. No inline comment = no !procedure conflict.
+		return decl + "\n' " + comment
 	}
-	return line
+	return decl
 }
 
 // plantUMLResourceComment merges resource-level fields with the first instance
diff --git a/models/workflow/workflow.go b/models/workflow/workflow.go
index 83c0254..b62a909 100644
--- a/models/workflow/workflow.go
+++ b/models/workflow/workflow.go
@@ -149,15 +149,46 @@ func (d *Workflow) ExtractFromPlantUML(plantUML multipart.File, request *tools.A
 		},
 	}
 	graphVarName := map[string]graph.GraphItem{}
-	scanner := bufio.NewScanner(plantUML)
 
+	// Collect all lines first to support look-ahead (comment on the line after
+	// the declaration, as produced by ToPlantUML).
+	scanner := bufio.NewScanner(plantUML)
+	var lines []string
 	for scanner.Scan() {
-		line := scanner.Text()
+		lines = append(lines, scanner.Text())
+	}
+	if err := scanner.Err(); err != nil {
+		return d, err
+	}
+
+	for i, line := range lines {
+		trimmed := strings.TrimSpace(line)
+
+		// Skip pure comment lines and PlantUML directives — they must never be
+		// parsed as resource declarations or links. Without this guard, a comment
+		// like "' source: http://my-server.com" would match the "-" link check.
+		if strings.HasPrefix(trimmed, "'") ||
+			strings.HasPrefix(trimmed, "!") ||
+			strings.HasPrefix(trimmed, "@") ||
+			trimmed == "" {
+			continue
+		}
+
+		// Build the parse line: if the current line has no inline comment and the
+		// next line is a pure comment, append it so parsers receive one combined line.
+		// Also handles the legacy inline-comment format unchanged.
+		parseLine := line
+		if !strings.Contains(line, "'") && i+1 < len(lines) {
+			if next := strings.TrimSpace(lines[i+1]); strings.HasPrefix(next, "'") {
+				parseLine = line + " " + next
+			}
+		}
+
 		for n, new := range resourceCatalog {
-			if strings.Contains(line, n+"(") && !strings.Contains(line, "!procedure") { // should exclude declaration of type.
+			if strings.Contains(line, n+"(") && !strings.Contains(line, "!procedure") && !strings.Contains(line, "!define") { // exclude macro declarations
 				newRes := new()
 				newRes.SetID(uuid.New().String())
-				varName, graphItem, err := d.extractResourcePlantUML(line, newRes, n, request.PeerID)
+				varName, graphItem, err := d.extractResourcePlantUML(parseLine, newRes, n, request.PeerID)
 				fmt.Println(varName, graphItem, err)
 				if err != nil {
 					return d, err
@@ -167,25 +198,25 @@ func (d *Workflow) ExtractFromPlantUML(plantUML multipart.File, request *tools.A
 				}
 				continue
 			} else if strings.Contains(line, "-->") {
-				err := d.extractLink(line, graphVarName, "-->", false)
+				err := d.extractLink(parseLine, graphVarName, "-->", false)
 				if err != nil {
 					fmt.Println(err)
 					continue
 				}
 			} else if strings.Contains(line, "<--") {
-				err := d.extractLink(line, graphVarName, "<--", true)
+				err := d.extractLink(parseLine, graphVarName, "<--", true)
 				if err != nil {
 					fmt.Println(err)
 					continue
 				}
 			} else if strings.Contains(line, "--") {
-				err := d.extractLink(line, graphVarName, "--", false)
+				err := d.extractLink(parseLine, graphVarName, "--", false)
 				if err != nil {
 					fmt.Println(err)
 					continue
 				}
 			} else if strings.Contains(line, "-") {
-				err := d.extractLink(line, graphVarName, "-", false)
+				err := d.extractLink(parseLine, graphVarName, "-", false)
 				if err != nil {
 					fmt.Println(err)
 					continue
@@ -193,9 +224,6 @@ func (d *Workflow) ExtractFromPlantUML(plantUML multipart.File, request *tools.A
 			}
 		}
 	}
-	if err := scanner.Err(); err != nil {
-		return d, err
-	}
 	d.generateResource(d.GetResources(tools.DATA_RESOURCE), request)
 	d.generateResource(d.GetResources(tools.PROCESSING_RESOURCE), request)
 	d.generateResource(d.GetResources(tools.STORAGE_RESOURCE), request)