When Angelo Castelli bustled belatedly into the Prince George's County school board's Feb. 11 meeting, he had a good excuse.

He had just come from the White House.

It seems that Castelli's 15-year-old daughter, Jennifer, wanted to go with her father last month to Suitland High School, the site of President Reagan's latest major educational policy speech.

For security reasons, she could not go. She had to attend her own classes at Oxon Hill.

"She said, 'Gee Dad. If you get to talk to him, why don't you invite him to dinner?' " Castelli recounted.

So later at Suitland, when the president walked down a receiving line of officials that included board members, Castelli told the president what his daughter had said.

"He said, 'Well, I am a very busy man. Tell that young lady I appreciate it very much.' He proceeded . . . suddenly he turned around. " 'By the way, you tell that young lady to write me a letter,' " Castelli said.

A few hours later, only minutes after her father gave her the instructions, Jennifer Castelli had composed her letter inviting the president to dinner. It ended with "P.S. My mom's a great cook!" Her father changed one word and mailed it the next day.

About a week later, Jennifer received a reply from the White House.

"When I got the letter back, that was the greatest thing. I didn't even expect to go to the White House," she said.

Jennifer wrote a second letter and received a phone call from the White House inviting her to a meeting with the president.

"From there, it was history," Castelli said. "It cost me a few hundred dollars." It was not a fee for entrance, but a pittance for three new dresses and three new "hairdos" for his wife and two daughters, he said.

This has to be one of the worst weeks for Robert K. Kendal, Montgomery County's director of management and budget. He is rushing to help County Executive Sidney Kramer put the final touches on next year's operating budget.

The budget is to be unveiled Monday, and among the headaches of the last week is getting the numbers to come out right and fending off the attempts of reporters wanting to get a jump on the budget -- particularly to find out if there will be a property tax increase.

But there are things Kendal can be grateful for. As Kramer on Monday unveiled some suggestions on changing government, one reporter asked whether any of the proposals would be included in next year's budget.

No, Kramer said, explaining he didn't know what he would eventually decide on. There just isn't enough time, he said.

From the back of the room came Kendal's heartfelt comment. "Thank you."

Howard County residents who attended a public hearing on proposed capital projects last week were treated to an unexpected game of musical chairs. More than 200 people turned out for the annual lobbying ritual before the county planning board, about 10 times the number for which there was seating.

After the county council, which also had a hearing scheduled for that Tuesday night, turned down a last-minute request to let the planning Grapevine items were compiled by staff writers Jo-Ann Armao, Lisa Leff, Peter Perl, Lexie Verdon and Rochelle Riley. board use its more spacious meeting rooms, planning department staffers had no choice but to close the doors and leave most of the speakers milling about in the hallway until their topic came up on the agenda.

G.W. (Bill) Eklof, a county trial magistrate in the days before Howard had circuit court judges, was among those visibly irritated by the "shabby treatment."

"If this meeting is an example of how this county is being run, we're in sad shape," said Eklof, 76, who had come out with his wife and two neighbors to oppose a road project for their Ellicott City neighborhood. "I haven't been up here to testify for 20 years, and at the rate things are going, I won't be back for another 20."

For the first time in its 16-year history, the Columbia Democratic CLub won't be endorsing a presidential candidate in Maryland's primary election. At the liberal club's Feb. 17 "convention," none of the seven candidates then vying for their party's nomination was able to garner a majority of the votes. Massachusetts Gov. Michael S. Dukakis came the closest, but after a third ballot was still three votes shy of winning a majority of the 70 club members present. Jesse L. Jackson came in second, and Sen. Paul Simon of Illinois placed third.

The top brass of the AFL-CIO gathered for its winter meeting at the resort community of Bal Harbour, Fla., last week. It's the annual gathering of powerful union leaders of the 13 million-member labor federation, and it's also a popular spot for politicians who are seeking union endorsements -- and campaign donations.

So who should show up at the bar of the Sheraton Bal Harbour around midnight to work the crowd and talk up his candidacy but Del. Peter Franchot of Takoma Park, who is running for the Democratic nomination for the 8th Congressional District seat.

Franchot, who has been endorsed by various Maryland labor organizations, turned up to shake a few hands and present his case for an AFL-CIO endorsement, which could be a big financial boost for his uphill battle against Rep. Constance A. Morella (R-Md.).

Meanwhile, Morella was busy proving her allegiances closer to home. Morella made a small wager with Rep. Patricia Schroeder (D-Colo.) on the outcome of the Super Bowl between the Washington Redskins and the favored Denver Broncos. The loser agreed to wear the winning team's T-shirt on the Capitol steps. But Morella, who said she's a longtime Redskins fan, upped the ante early this month. She brought along a "hog nose" for Schroeder.

"Pat's a good friend and a good sport, but she backed the wrong team," Morella said. AFTER WORDS

"Believe it or not, we had a hog who would climb over fences and do just about anything to get away. He turned into sausage."

-- Howard County Council member Charles Feaga on whether owners of dogs caught roaming free more than three times should be forbidden to have pets