RSS Keyword Filters: Include and Exclude Rules for Auto-Posting

Short answer: RSS keyword filters decide which feed items are allowed to become social posts. An include list posts only items that contain at least one of your chosen words, and an exclude list blocks items that contain words you never want shared. Keep both lists short and specific, check them against the title and description text your feed really contains, and test them on recent items before you connect a live account.

Most feeds carry more than you want to publish. A news site mixes local stories with national wire copy, a shop feed mixes new products with restocks, and a company blog mixes product news with job ads and event recaps. Keyword filters are the simplest way to send only the right items to each channel without building separate feeds in your CMS. This guide explains how include and exclude rules work, how to choose the words, the mistakes that make filters leak or block too much, and how to test them before they go live.

What an RSS keyword filter actually does

A keyword filter is a rule that sits between the feed and the social account. Every time the auto-poster finds a new item, it reads the text of that item and compares it with your word lists. If the item passes, it is posted. If it fails, it is skipped and nothing appears on the network.

There are two kinds of rules:

• Include rules (sometimes called whitelist or allow rules). The item is posted only if it contains at least one of the listed keywords. Everything else is ignored.
• Exclude rules (blacklist or block rules). The item is posted unless it contains one of the listed keywords.

Used together, the include list narrows the feed to a topic and the exclude list removes exceptions inside that topic. For example, a cycling club that shares a regional sports feed could include cycling, bike و race, and exclude motorbike so motor sport stories do not slip through.

Which parts of a feed item are checked

A filter can only see the text that the feed provides. In an RSS 2.0 item that usually means the title and the description; in Atom it is the title and the summary أو content. The structure of these elements is defined in the RSS 2.0 specification, and the basics are explained in RSS feed XML anatomy.

This has practical consequences:

• Short descriptions hide words. If your feed carries only the first 20 words of each article, a keyword that appears in the third paragraph is invisible to the filter.
• HTML is part of the text. Descriptions often contain markup, image captions and link text. A filter for sale can match a file name such as sale-banner.jpg inside an image tag.
• Categories may not be included. The category elements of an item are separate from the title and description. If you want to route by category, use a category feed or category rules instead, as described in how to filter your RSS feed by category.

Before writing a single rule, open the raw feed in a browser or with a command-line tool and read three or four items. Note exactly which words appear in their titles and descriptions. You will often find that the word you planned to filter on is not there at all.

Include or exclude: which one to start with

The choice depends on what the feed looks like and what the channel is for.

A useful rule of thumb: include lists are precise but fragile, because a new article that uses a synonym is silently skipped. Exclude lists are forgiving but leaky, because a new unwanted topic passes until you add its word. Decide which failure you can live with on each channel. Missing a post is usually cheaper than publishing the wrong one on a company page.

How to choose good keywords

Good filter words are distinctive. They appear in the items you want and almost never in the items you do not. Some practical guidelines:

1. Prefer specific terms over general ones. webinar is a better include word for an events channel than event, which also appears in news about events you did not organise.
2. Cover the variants people actually write. If writers use both e-book و ebook, list both. Think about singular and plural forms, British and American spelling, and abbreviations.
3. Watch for words inside other words. Depending on how matching works, art can match start, party و article. Choose longer, unambiguous words, or test carefully.
4. Use the language of the feed. A multilingual site may need the same keyword in each language, or a separate filter per language feed. See multilingual RSS automation.
5. Agree on fixed words with writers. The most reliable filter is a word your team puts into titles on purpose, such as a prefix like Release: أو Hiring:.

The last point is worth repeating. Filters work best when the content team knows they exist. A short note in your style guide, such as all job ads start with Hiring, turns a guessing game into a dependable rule.

Common filter recipes

These patterns cover most real setups. Adapt the words to your own feed.

• Keep job ads off the main page. Exclude hiring, vacancy و job opening on the brand channel, and create a second target for a careers account that includes the same words.
• Share only product launches. On a shop feed, include new, launch و introducing, and exclude restock و back in stock.
• Local news only. On a regional news feed, include the names of the towns you cover. Add common spellings and the names of nearby districts.
• Remove sponsored items. Exclude sponsored, advertorial و partner content, if your publisher labels such items in the title.
• Avoid sensitive topics on a cheerful channel. Exclude words linked to accidents, deaths or crime on a channel aimed at families. This is covered in more depth in brand safety for auto-posted content.

One feed can feed several targets, each with its own filter. That is often cleaner than maintaining several feeds: the same blog feed can go to a developer community with a technical include list and to a general audience with an exclude list for internal topics.

Mistakes that make filters leak or block too much

Most filter problems come from a small set of causes:

• Too many include words. A list of thirty words becomes a near copy of the full feed. Keep include lists to a handful of distinctive terms.
• Exclude words that are too common. Excluding free to block giveaways also blocks free shipping, gluten-free و free webinar.
• Relying on the description when the feed has no description. Some feeds, especially those generated by page scrapers, carry only titles. Then only the title is checked.
• Changing the feed format later. If you switch the feed from full text to excerpts, words that used to be visible may disappear. The difference is explained in full-text vs excerpt RSS feeds.
• Forgetting the filter exists. Months later, someone wonders why a post never appeared. Write down every filter and the reason for it.

When an item is skipped by a filter, it is usually skipped for good on that target, because the auto-poster has already seen it. Changing the filter afterwards will not bring back old items unless your tool offers a way to post older items again.

How to test keyword filters before going live

Never connect a new filter directly to your main account. A short test saves you from both silent gaps and embarrassing posts.

1. Collect a sample. Save the last 20 to 50 items of the feed. Mark by hand which ones should be posted on the channel.
2. Apply the rules on paper. Go through the sample and check which items your include and exclude words would let through. Compare with your manual marks.
3. Use a test target. Connect the filtered feed to a private channel, such as a private Telegram channel or a test Discord server, and let it run for a few days.
4. Review both sides. Look at what was posted and, just as important, at what was not. Open the feed and find items that should have passed.
5. Move to the real account. Once the test target looks right for several days, connect the same rules to the live account.

Validate the feed itself at the same time. A filter cannot help if the feed is malformed or the description is empty. The W3C Feed Validation Service shows structural problems, and RSS feed validation before auto-posting explains what to fix.

Keyword filters, categories and separate feeds compared

Keyword filters are one of three ways to control what is posted, and each has a place.

• Separate feeds from your CMS, such as a category or tag feed, are the most reliable when you own the site. The CMS decides what belongs where, and the auto-poster simply posts everything in that feed.
• Category rules use the category elements of each item. They are precise when the site tags content consistently.
• Keyword filters work on any feed, including feeds you do not control, and need no changes to the source site. They are the right tool for third-party feeds, quick exceptions and safety nets.

In practice the best setups combine them: a category feed to get the right topic, plus a short exclude list as a safety net for words that should never appear on that channel. Routing topics to different accounts is explained in category filtering for auto-posting.

Maintaining filters over time

Feeds change. Writers adopt new terms, products get new names, and publishers redesign their feeds. Plan a short review every month or quarter:

• Read the last few weeks of posts on each filtered channel and look for anything that should not be there.
• Open the feed and look for items that were skipped but should have been posted.
• Add new variants of your include words and new unwanted terms to the exclude list.
• Remove words that no longer serve a purpose, so the lists stay short and understandable.

Keep a simple document with each target, its include and exclude lists, and one sentence about why each word is there. When several people manage the setup, this record prevents someone from deleting a safety word without knowing why it was added.

How PostRSS handles keyword filters

PostRSS has posted RSS and Atom feeds to social networks since 2014. For each source you can list keywords to include or exclude; PostRSS matches them in the item title and description and posts only the items that fit. The same feed can be connected to several targets, each with its own settings, so one blog can feed a brand page, a careers channel and a community server with different rules. Filters sit alongside other controls such as hashtags from item categories, UTM parameters, posting windows and the choice of post text, across 66 supported networks, messengers, team chats and blogs. See the PostRSS features page for details and the pricing page for plan limits. More guides on this subject are under the Feed Filtering tag.

Related reading

• How to filter your RSS feed by category before auto-posting
• Brand safety for auto-posted content
• How many social accounts can you connect to one RSS feed

The bottom line

Keyword filters turn a broad feed into a feed that fits each channel. Use include rules when only a small part of the feed belongs on a channel and exclude rules to block known exceptions. Choose distinctive words that really appear in the title and description, cover their variants, and agree on fixed title words with your writers. Test every new filter on a private target, review both what was posted and what was skipped, and keep a written record so the rules stay understandable as the feed changes.

FAQ

What is the difference between include and exclude keywords?

Include keywords allow only items that contain at least one of the listed words, and everything else is skipped. Exclude keywords block items that contain any of the listed words, and everything else is posted.

Do keyword filters check the full article?

No. A filter can only check the text inside the feed, usually the title and the description or summary. If the feed carries only a short excerpt, words further down the article are not visible to the filter.

Can I use include and exclude rules together?

Yes, and it is often the best approach. The include list narrows the feed to a topic, and the exclude list removes unwanted items inside that topic, such as sponsored posts or restocks.

Why was an item skipped even though it contains my keyword?

The word may appear only in the full article and not in the feed text, it may be spelled differently, or it may also match an exclude word. Open the raw feed and read the exact title and description of that item.

Are keyword filters better than category feeds?

Not always. When you own the site, a category or tag feed is usually more reliable. Keyword filters are best for feeds you do not control, for quick exceptions and as a safety net on brand-sensitive channels.