diff --git a/backend/src/modules/master/dto/create-tag.dto.ts b/backend/src/modules/master/dto/create-tag.dto.ts
index 9e3879f..13028c7 100644
--- a/backend/src/modules/master/dto/create-tag.dto.ts
+++ b/backend/src/modules/master/dto/create-tag.dto.ts
@@ -5,7 +5,7 @@ export class CreateTagDto {
   @ApiProperty({ example: 'URGENT', description: 'ชื่อ Tag' })
   @IsString()
   @IsNotEmpty()
-  tag_name!: string; // เพิ่ม !
+  tagName!: string;
 
   @ApiProperty({ example: 'คำอธิบาย', description: 'คำอธิบาย' })
   @IsString()
@@ -19,7 +19,7 @@ export class CreateTagDto {
   })
   @IsString()
   @IsOptional()
-  color_code?: string;
+  colorCode?: string;
 
   @ApiProperty({
     example: 1,
@@ -27,5 +27,5 @@ export class CreateTagDto {
     required: false,
   })
   @IsOptional()
-  project_id?: number | string;
+  projectId?: number | string;
 }
diff --git a/backend/src/modules/master/dto/search-tag.dto.ts b/backend/src/modules/master/dto/search-tag.dto.ts
index 1561669..ca6ede6 100644
--- a/backend/src/modules/master/dto/search-tag.dto.ts
+++ b/backend/src/modules/master/dto/search-tag.dto.ts
@@ -2,16 +2,17 @@
 
 import { IsString, IsOptional, IsInt, Min } from 'class-validator';
 import { Type } from 'class-transformer';
-import { ApiPropertyOptional } from '@nestjs/swagger';
+import { ApiPropertyOptional, ApiProperty } from '@nestjs/swagger';
 
 export class SearchTagDto {
-  @ApiPropertyOptional({
-    description: 'ID โครงการ (ใช้กรอง Tag ของแต่ละโปรเจกต์)',
+  @ApiProperty({
+    example: 1,
+    description:
+      'Project ID or UUID (ใช้กรอง Tag ของแต่ละโปรเจกต์) - ADR-019: Accept UUID',
+    required: false,
   })
   @IsOptional()
-  @Type(() => Number)
-  @IsInt()
-  project_id?: number;
+  projectId?: number | string;
 
   @ApiPropertyOptional({ description: 'คำค้นหา (ชื่อ Tag หรือ คำอธิบาย)' })
   @IsOptional()
diff --git a/backend/src/modules/master/master.service.ts b/backend/src/modules/master/master.service.ts
index d5b0c38..3c0837f 100644
--- a/backend/src/modules/master/master.service.ts
+++ b/backend/src/modules/master/master.service.ts
@@ -303,25 +303,24 @@ export class MasterService {
       .createQueryBuilder('tag')
       .leftJoinAndSelect('tag.project', 'project');
 
-    if (query?.project_id) {
-      // In Tags, we use project_id (INT) directly or resolve if UUID passed via query
+    if (query?.projectId) {
       const internalId = await this.uuidResolver.resolveProjectId(
-        query.project_id
+        query.projectId
       );
-      qb.andWhere('tag.project_id = :projectId', {
+      qb.andWhere('tag.projectId = :projectId', {
         projectId: internalId,
       });
     }
 
     if (query?.search) {
       qb.andWhere(
-        '(tag.tag_name LIKE :search OR tag.description LIKE :search)',
+        '(tag.tagName LIKE :search OR tag.description LIKE :search)',
         {
           search: `%${query.search}%`,
         }
       );
     }
-    qb.orderBy('tag.tag_name', 'ASC');
+    qb.orderBy('tag.tagName', 'ASC');
     if (query?.page && query?.limit) {
       const page = query.page;
       const limit = query.limit;
@@ -342,11 +341,13 @@ export class MasterService {
   }
 
   async createTag(dto: CreateTagDto, userId: number) {
-    const internalProjectId = dto.project_id
-      ? await this.uuidResolver.resolveProjectId(dto.project_id)
+    const internalProjectId = dto.projectId
+      ? await this.uuidResolver.resolveProjectId(dto.projectId)
       : null;
     const tag = this.tagRepo.create({
-      ...dto,
+      tagName: dto.tagName,
+      colorCode: dto.colorCode,
+      description: dto.description,
       projectId: internalProjectId,
       createdBy: userId,
     });
@@ -355,10 +356,18 @@ export class MasterService {
 
   async updateTag(id: number, dto: UpdateTagDto) {
     const tag = await this.findOneTag(id);
-    if (dto.project_id) {
-      dto.project_id = await this.uuidResolver.resolveProjectId(dto.project_id);
+    let internalProjectId = dto.projectId;
+    if (dto.projectId) {
+      internalProjectId = await this.uuidResolver.resolveProjectId(
+        dto.projectId
+      );
     }
-    Object.assign(tag, dto);
+    Object.assign(tag, {
+      tagName: dto.tagName,
+      colorCode: dto.colorCode,
+      description: dto.description,
+      projectId: internalProjectId,
+    });
     return this.tagRepo.save(tag);
   }
 
diff --git a/frontend/app/(admin)/admin/doc-control/reference/tags/page.tsx b/frontend/app/(admin)/admin/doc-control/reference/tags/page.tsx
index f971cc5..3d4f34c 100644
--- a/frontend/app/(admin)/admin/doc-control/reference/tags/page.tsx
+++ b/frontend/app/(admin)/admin/doc-control/reference/tags/page.tsx
@@ -24,7 +24,7 @@ export default function TagsPage() {
 
   const columns: ColumnDef<Tag>[] = [
     {
-      accessorKey: 'project_id',
+      accessorKey: 'projectId',
       header: 'Project',
       cell: ({ row }) => {
         const item = row.original as Tag & { project?: { id?: number | string; publicId?: string; projectName?: string; projectCode?: string } };
@@ -34,7 +34,7 @@ export default function TagsPage() {
       },
     },
     {
-      accessorKey: 'tag_name',
+      accessorKey: 'tagName',
       header: 'Tag Name',
       cell: ({ row }) => {
         const color = String(row.original.colorCode || 'default');
@@ -58,9 +58,9 @@ export default function TagsPage() {
 
   const formatPayload = (data: Record<string, unknown>) => {
     const payload = { ...data };
-    // ADR-019: project_id is now a UUID string or '__none__' for global
-    if (!payload.project_id || payload.project_id === '__none__') {
-      payload.project_id = null;
+    // ADR-019: projectId is now a UUID string or '__none__' for global
+    if (!payload.projectId || payload.projectId === '__none__') {
+      payload.projectId = null;
     }
     return payload;
   };
@@ -73,12 +73,12 @@ export default function TagsPage() {
       queryKey={['tags']}
       fetchFn={async () => {
         const items = await masterDataService.getTags();
-        // ADR-019: Map project_id INT → project UUID for edit mode select matching
+        // ADR-019: Map projectId INT → project UUID for edit mode select matching
         return items.map((item) => {
-          const rec = item as Tag & { project?: { id?: number | string; publicId?: string }; project_id?: number | string };
+          const rec = item as Tag & { project?: { id?: number | string; publicId?: string }; projectId?: number | string };
           return {
             ...item,
-            project_id: rec.project?.publicId || rec.project?.id || (rec.project_id ? String(rec.project_id) : null),
+            projectId: rec.project?.publicId || rec.project?.id || (rec.projectId ? String(rec.projectId) : null),
           } as Tag;
         });
       }}
@@ -90,7 +90,7 @@ export default function TagsPage() {
       columns={columns}
       fields={[
         {
-          name: 'project_id',
+          name: 'projectId',
           label: 'Project Scope',
           type: 'select',
           options: projectOptions,
diff --git a/frontend/components/correspondences/form.tsx b/frontend/components/correspondences/form.tsx
index fdb37ac..5eaf65d 100644
--- a/frontend/components/correspondences/form.tsx
+++ b/frontend/components/correspondences/form.tsx
@@ -439,81 +439,6 @@ export function CorrespondenceForm({ initialData, uuid }: { initialData?: Initia
         </div>
       </div>
 
-      {/* Subject */}
-      <div className="space-y-2">
-        <Label htmlFor="subject">Subject *</Label>
-        <Input id="subject" {...register('subject')} placeholder="Enter subject" />
-        {errors.subject && <p className="text-sm text-destructive">{errors.subject.message}</p>}
-      </div>
-
-      {/* Body */}
-      <div className="space-y-2">
-        <Label htmlFor="body">Body (Content)</Label>
-        <Textarea id="body" {...register('body')} rows={6} placeholder="Enter letter content..." />
-      </div>
-
-      {/* Date Fields */}
-      <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-4">
-        <div className="space-y-2">
-          <Label htmlFor="documentDate">Document Date</Label>
-          <Input
-            id="documentDate"
-            type="date"
-            {...register('documentDate')}
-            onChange={(e) => {
-              const val = e.target.value;
-              setValue('documentDate', val, { shouldValidate: true, shouldDirty: true });
-              if (val) {
-                setValue('issuedDate', val, { shouldValidate: true, shouldDirty: true });
-                setValue('receivedDate', val, { shouldValidate: true, shouldDirty: true });
-                const d = new Date(val);
-                d.setDate(d.getDate() + 7);
-                setValue('dueDate', d.toISOString().split('T')[0], { shouldValidate: true, shouldDirty: true });
-              }
-            }}
-          />
-        </div>
-        <div className="space-y-2">
-          <Label htmlFor="issuedDate">Issued Date</Label>
-          <Input id="issuedDate" type="date" {...register('issuedDate')} />
-        </div>
-        <div className="space-y-2">
-          <Label htmlFor="receivedDate">Received Date</Label>
-          <Input
-            id="receivedDate"
-            type="date"
-            {...register('receivedDate')}
-            onChange={(e) => {
-              const val = e.target.value;
-              setValue('receivedDate', val, { shouldValidate: true, shouldDirty: true });
-              if (val) {
-                const d = new Date(val);
-                d.setDate(d.getDate() + 7);
-                setValue('dueDate', d.toISOString().split('T')[0], { shouldValidate: true, shouldDirty: true });
-              }
-            }}
-          />
-        </div>
-        <div className="space-y-2">
-          <Label htmlFor="dueDate">Due Date</Label>
-          <Input id="dueDate" type="date" {...register('dueDate')} />
-        </div>
-      </div>
-
-      {/* Remarks */}
-      <div className="grid grid-cols-1 gap-4">
-        <div className="space-y-2">
-          <Label htmlFor="remarks">Remarks</Label>
-          <Input id="remarks" {...register('remarks')} placeholder="Optional remarks" />
-        </div>
-      </div>
-
-      {/* Description */}
-      <div className="space-y-2">
-        <Label htmlFor="description">Description (Internal Note)</Label>
-        <Textarea id="description" {...register('description')} rows={2} placeholder="Enter description..." />
-      </div>
-
       {/* Organizations */}
       <div className="grid grid-cols-1 md:grid-cols-2 gap-6">
         <div className="space-y-2">
@@ -589,6 +514,81 @@ export function CorrespondenceForm({ initialData, uuid }: { initialData?: Initia
         </div>
       </div>
 
+      {/* Subject */}
+      <div className="space-y-2">
+        <Label htmlFor="subject">Subject *</Label>
+        <Input id="subject" {...register('subject')} placeholder="Enter subject" />
+        {errors.subject && <p className="text-sm text-destructive">{errors.subject.message}</p>}
+      </div>
+
+      {/* Body */}
+      <div className="space-y-2">
+        <Label htmlFor="body">Body (Content)</Label>
+        <Textarea id="body" {...register('body')} rows={6} placeholder="Enter letter content..." />
+      </div>
+
+      {/* Date Fields */}
+      <div className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 gap-4">
+        <div className="space-y-2">
+          <Label htmlFor="documentDate">Document Date</Label>
+          <Input
+            id="documentDate"
+            type="date"
+            {...register('documentDate')}
+            onChange={(e) => {
+              const val = e.target.value;
+              setValue('documentDate', val, { shouldValidate: true, shouldDirty: true });
+              if (val) {
+                setValue('issuedDate', val, { shouldValidate: true, shouldDirty: true });
+                setValue('receivedDate', val, { shouldValidate: true, shouldDirty: true });
+                const d = new Date(val);
+                d.setDate(d.getDate() + 7);
+                setValue('dueDate', d.toISOString().split('T')[0], { shouldValidate: true, shouldDirty: true });
+              }
+            }}
+          />
+        </div>
+        <div className="space-y-2">
+          <Label htmlFor="issuedDate">Issued Date</Label>
+          <Input id="issuedDate" type="date" {...register('issuedDate')} />
+        </div>
+        <div className="space-y-2">
+          <Label htmlFor="receivedDate">Received Date</Label>
+          <Input
+            id="receivedDate"
+            type="date"
+            {...register('receivedDate')}
+            onChange={(e) => {
+              const val = e.target.value;
+              setValue('receivedDate', val, { shouldValidate: true, shouldDirty: true });
+              if (val) {
+                const d = new Date(val);
+                d.setDate(d.getDate() + 7);
+                setValue('dueDate', d.toISOString().split('T')[0], { shouldValidate: true, shouldDirty: true });
+              }
+            }}
+          />
+        </div>
+        <div className="space-y-2">
+          <Label htmlFor="dueDate">Due Date</Label>
+          <Input id="dueDate" type="date" {...register('dueDate')} />
+        </div>
+      </div>
+
+      {/* Remarks */}
+      <div className="grid grid-cols-1 gap-4">
+        <div className="space-y-2">
+          <Label htmlFor="remarks">Remarks</Label>
+          <Input id="remarks" {...register('remarks')} placeholder="Optional remarks" />
+        </div>
+      </div>
+
+      {/* Description */}
+      <div className="space-y-2">
+        <Label htmlFor="description">Description (Internal Note)</Label>
+        <Textarea id="description" {...register('description')} rows={2} placeholder="Enter description..." />
+      </div>
+
       {/* Importance */}
       <div className="space-y-2">
         <Label>Importance</Label>
diff --git a/frontend/components/rfas/form.tsx b/frontend/components/rfas/form.tsx
index 8c854fc..1cd6647 100644
--- a/frontend/components/rfas/form.tsx
+++ b/frontend/components/rfas/form.tsx
@@ -345,28 +345,7 @@ export function RFAForm() {
         <h3 className="text-lg font-semibold mb-4">RFA Information</h3>
 
         <div className="space-y-4">
-          <div>
-            <Label htmlFor="subject">Subject *</Label>
-            <Input id="subject" {...register('subject')} placeholder="Enter subject" />
-            {errors.subject && <p className="text-sm text-destructive mt-1">{errors.subject.message}</p>}
-          </div>
-
-          <div>
-            <Label htmlFor="body">Body (Content)</Label>
-            <Textarea id="body" {...register('body')} rows={4} placeholder="Enter content..." />
-          </div>
-
-          <div>
-            <Label htmlFor="remarks">Remarks</Label>
-            <Input id="remarks" {...register('remarks')} placeholder="Optional remarks" />
-          </div>
-
-          <div>
-            <Label htmlFor="description">Description</Label>
-            <Input id="description" {...register('description')} placeholder="Enter key description" />
-          </div>
-
-          <div>
+                    <div>
             <Label>Project *</Label>
             <Select
               value={selectedProjectId || undefined}
@@ -540,6 +519,28 @@ export function RFAForm() {
               )}
             </div>
           </div>
+          <div>
+            <Label htmlFor="subject">Subject *</Label>
+            <Input id="subject" {...register('subject')} placeholder="Enter subject" />
+            {errors.subject && <p className="text-sm text-destructive mt-1">{errors.subject.message}</p>}
+          </div>
+
+          <div>
+            <Label htmlFor="body">Body (Content)</Label>
+            <Textarea id="body" {...register('body')} rows={4} placeholder="Enter content..." />
+          </div>
+
+          <div>
+            <Label htmlFor="remarks">Remarks</Label>
+            <Input id="remarks" {...register('remarks')} placeholder="Optional remarks" />
+          </div>
+
+          <div>
+            <Label htmlFor="description">Description</Label>
+            <Input id="description" {...register('description')} placeholder="Enter key description" />
+          </div>
+
+
         </div>
       </Card>
 
diff --git a/output/pdf/lcbp3-app-summary.md b/output/pdf/lcbp3-app-summary.md
new file mode 100644
index 0000000..96f5d14
--- /dev/null
+++ b/output/pdf/lcbp3-app-summary.md
@@ -0,0 +1,62 @@
+# LCBP3-DMS App Summary
+
+## What It Is
+
+LCBP3-DMS is a document management system for the Laem Chabang Port Phase 3 construction project. Repo docs describe it as a system for managing construction documents, approvals, workflows, and cross-organization communication. The codebase is split into a Next.js frontend and a NestJS backend, with MariaDB, Redis, and Elasticsearch in the application stack.
+
+## Who It's For
+
+Primary users are document-heavy construction project teams working across multiple organizations. Repo evidence points especially to Document Control, Org Admin, Engineer/Reviewer, Superadmin, consultants, supervisors, and contractors.
+
+## What It Does
+
+- Manages correspondence records between organizations.
+- Supports RFA workflows for technical approval requests.
+- Tracks contract and shop drawings.
+- Handles transmittals and circulation sheets.
+- Applies 4-level RBAC / CASL-based access control.
+- Generates document numbers with Redis-backed locking rules.
+- Supports file upload and attachment handling with cleanup jobs.
+- Exposes admin screens for users, orgs, projects, workflows, numbering, and audit logs.
+- Provides search through an Elasticsearch-backed search module.
+- Includes notification processing and a migration area for legacy document import.
+
+\newpage
+
+## How It Works
+
+### Frontend
+
+- `frontend/` is a Next.js 16 App Router app.
+- Route groups in `frontend/app/` show three main surfaces: `(auth)`, `(dashboard)`, and `(admin)`.
+- Installed frontend libraries indicate form validation and data fetching with React Hook Form, Zod, TanStack Query, and Zustand.
+- `frontend/app/api/auth/[...nextauth]/route.ts`: Not found in repo via direct read during this task, but the route file exists in the app tree.
+
+### Backend
+
+- `backend/src/main.ts` boots a NestJS 11 app with Helmet, CORS, 50 MB body limits, global validation, response transformation, exception filtering, and Swagger.
+- `backend/src/app.module.ts` wires Config, TypeORM for MariaDB, BullMQ, Redis, scheduling, throttling, logging, monitoring, resilience, and feature modules.
+- Feature modules present in code include auth, user, project, organization, contract, correspondence, RFA, drawing, transmittal, circulation, workflow-engine, document-numbering, search, notification, audit-log, dashboard, master, and migration.
+
+### Data Flow
+
+- Browser -> Next.js UI -> backend API under `/api`.
+- Backend validates requests, applies guards/interceptors, and persists entities to MariaDB through TypeORM.
+- Redis is used in the running architecture for BullMQ queues and Redis module integration; repo specs also tie Redis to locking, caching, and idempotency patterns.
+- Search requests flow through the NestJS search module into Elasticsearch.
+- Notification work is queued through BullMQ and also exposes a WebSocket gateway.
+- Migration services write through backend modules and the shared file-storage module rather than direct client-side data access.
+
+## How To Run
+
+1. Install workspace dependencies with `pnpm install` at repo root.
+2. Start local infra from [`backend/docker-compose.yml`](/E:/np-dms/lcbp3/backend/docker-compose.yml) to bring up MariaDB, Redis, and Elasticsearch.
+3. Prepare env files: `frontend/.env.example` -> `frontend/.env.local`; backend example env file: Not found in repo.
+4. Load the SQL schema and seed data using the commands documented in [`README.md`](/E:/np-dms/lcbp3/README.md).
+5. Run backend with `pnpm run start:dev` in `backend/`.
+6. Run frontend with `pnpm run dev` in `frontend/`.
+
+## Notes
+
+- Minimal dev URLs from repo docs: frontend `http://localhost:3000`, backend `http://localhost:3001`, Swagger `/docs`.
+- Exact production deployment topology is documented, but this summary keeps only the minimum local-start path.